feat: implement interactive temperature chart dashboard with runway trend visualization and multi-source data collection support

frontend/components/dashboard/scan-terminal/LiveTemperatureThresholdChart.tsx

@@ -390,6 +390,7 @@ export function LiveTemperatureThresholdChart({
 
   const cityThresholds = useMemo(() => {
     if (!row || !allRows || !allRows.length) return [];
+    const tempSymbol = row.temp_symbol || "°C";
     const cityKey = String(row.city || "").toLowerCase().trim();
     const sameCityRows = allRows.filter(
       (r) => String(r.city || "").toLowerCase().trim() === cityKey
@@ -409,7 +410,7 @@ export function LiveTemperatureThresholdChart({
 
       list.push({
         threshold: t,
-        label: r.target_label || `${t}°C`,
+        label: r.target_label || `${t}${tempSymbol}`,
         isBreached,
         kind,
       });
@@ -564,6 +565,7 @@ export function LiveTemperatureThresholdChart({
           isEn={isEn}
           compact={compact}
           timeframe={timeframe}
+          tempSymbol={row?.temp_symbol || "°C"}
           runwayHeaderLabel={runwayHeaderLabel}
           metarHeaderLabel={metarHeaderLabel}
           runwayHighLabel={runwayHighLabel}
@@ -583,11 +585,11 @@ export function LiveTemperatureThresholdChart({
         />
 
         {timeframe === "1D" && !compact && (
-          <TemperatureRunwayDetails isEn={isEn} plates={runwayPlates} />
+          <TemperatureRunwayDetails isEn={isEn} plates={runwayPlates} tempSymbol={row?.temp_symbol || "°C"} />
         )}
 
         {timeframe === "1D" && !compact && (
-          <ModelCurvesSummary isEn={isEn} activeSeries={activeSeries} />
+          <ModelCurvesSummary isEn={isEn} activeSeries={activeSeries} tempSymbol={row?.temp_symbol || "°C"} />
         )}
 
         <TemperatureChartCanvas

frontend/components/dashboard/scan-terminal/ModelCurvesSummary.tsx

@@ -6,9 +6,11 @@ import { temp } from "@/components/dashboard/scan-terminal/utils";
 export function ModelCurvesSummary({
   isEn,
   activeSeries,
+  tempSymbol,
 }: {
   isEn: boolean;
   activeSeries: EvidenceSeries[];
+  tempSymbol: string;
 }) {
   const modelSeries = activeSeries.filter((s) => s.key.startsWith("model_curve_"));
   if (!modelSeries.length) return null;
@@ -25,7 +27,7 @@ export function ModelCurvesSummary({
             <span key={s.key} className="inline-flex items-center gap-1.5 font-mono">
               <span className="h-2 w-2 rounded-full shrink-0" style={{ backgroundColor: s.color }} />
               <span className="text-slate-700 font-bold">{s.label}</span>
-              <span className="text-slate-500">{temp(stats.latest)}</span>
+              <span className="text-slate-500">{temp(stats.latest, tempSymbol)}</span>
             </span>
           );
         })}

frontend/components/dashboard/scan-terminal/TemperatureChartCanvas.tsx

@@ -73,6 +73,7 @@ export function TemperatureChartCanvas({
 }) {
   const chartHostRef = useRef<HTMLDivElement | null>(null);
   const [chartSize, setChartSize] = useState({ width: 0, height: 0 });
+  const tempSymbol = row?.temp_symbol || "°C";
 
   useEffect(() => {
     const host = chartHostRef.current;
@@ -177,7 +178,7 @@ export function TemperatureChartCanvas({
             <YAxis
               orientation="right"
               tick={{ fontSize: 9, fill: "#64748b" }}
-              tickFormatter={(v) => `${Number(v).toFixed(0)}°`}
+              tickFormatter={(v) => `${Number(v).toFixed(0)}${tempSymbol}`}
               axisLine={{ stroke: "#cbd5e1" }}
               tickLine={false}
               domain={chartDomain}
@@ -186,8 +187,8 @@ export function TemperatureChartCanvas({
             {timeframe === "1D" && cityThresholds.map((t, idx) => {
               const isSelected = row && (Number(row.target_threshold ?? row.target_value) === t.threshold);
               const labelText = isEn
-                ? `${t.kind === "gte" ? "≥" : "≤"} ${t.threshold.toFixed(1)}° [${t.isBreached ? "Excluded" : "Active"}]`
+                ? `${t.kind === "gte" ? "≥" : "≤"} ${t.threshold.toFixed(1)}${tempSymbol} [${t.isBreached ? "Excluded" : "Active"}]`
-                : `${t.kind === "gte" ? "≥" : "≤"} ${t.threshold.toFixed(1)}° [${t.isBreached ? "已排除" : "活跃"}]`;
+                : `${t.kind === "gte" ? "≥" : "≤"} ${t.threshold.toFixed(1)}${tempSymbol} [${t.isBreached ? "已排除" : "活跃"}]`;
 
               return (
                 <ReferenceLine
@@ -221,17 +222,18 @@ export function TemperatureChartCanvas({
                   payload={props.payload as ReadonlyArray<{ payload?: Record<string, any> }> | undefined}
                   data={zoomedData}
                   series={activeSeries}
+                  tempSymbol={tempSymbol}
                 />
               )}
               formatter={(value: unknown) => {
                 if (Array.isArray(value)) {
                   const [low, high] = value;
                   if (typeof low === "number" && typeof high === "number") {
-                    return `${low.toFixed(1)}° - ${high.toFixed(1)}°`;
+                    return `${low.toFixed(1)}${tempSymbol} - ${high.toFixed(1)}${tempSymbol}`;
                   }
                 }
                 const num = Number(value);
-                return Number.isFinite(num) ? `${num.toFixed(2)}°` : String(value);
+                return Number.isFinite(num) ? `${num.toFixed(2)}${tempSymbol}` : String(value);
               }}
             />
             {hasRunwayData && (

frontend/components/dashboard/scan-terminal/TemperatureRunwayDetails.tsx

@@ -16,9 +16,11 @@ type RunwayPlate = {
 export function TemperatureRunwayDetails({
   isEn,
   plates,
+  tempSymbol,
 }: {
   isEn: boolean;
   plates: RunwayPlate[];
+  tempSymbol: string;
 }) {
   if (!plates.length) return null;
 
@@ -52,13 +54,13 @@ export function TemperatureRunwayDetails({
                 </span>
               )}
             </div>
-            <div>TDZ: <strong>{plate.tdzTemp !== null ? `${plate.tdzTemp.toFixed(1)}°C` : "--"}</strong></div>
+            <div>TDZ: <strong>{plate.tdzTemp !== null ? `${plate.tdzTemp.toFixed(1)}${tempSymbol}` : "--"}</strong></div>
-            <div>MID: <strong>{plate.midTemp !== null ? `${plate.midTemp.toFixed(1)}°C` : "--"}</strong></div>
+            <div>MID: <strong>{plate.midTemp !== null ? `${plate.midTemp.toFixed(1)}${tempSymbol}` : "--"}</strong></div>
-            <div>END: <strong>{plate.endTemp !== null ? `${plate.endTemp.toFixed(1)}°C` : "--"}</strong></div>
+            <div>END: <strong>{plate.endTemp !== null ? `${plate.endTemp.toFixed(1)}${tempSymbol}` : "--"}</strong></div>
-            <div>max: <strong>{plate.maxTemp !== null ? `${plate.maxTemp.toFixed(1)}°C` : "--"}</strong></div>
+            <div>max: <strong>{plate.maxTemp !== null ? `${plate.maxTemp.toFixed(1)}${tempSymbol}` : "--"}</strong></div>
-            <div>high: <strong>{plate.dailyHigh !== null ? `${plate.dailyHigh.toFixed(1)}°C` : "--"}</strong></div>
+            <div>high: <strong>{plate.dailyHigh !== null ? `${plate.dailyHigh.toFixed(1)}${tempSymbol}` : "--"}</strong></div>
             <div className={clsx(plate.trend_15m !== null && plate.trend_15m > 0 ? "text-orange-600 font-bold" : "text-slate-500")}>
-              15m: <strong>{plate.trend_15m !== null ? `${plate.trend_15m >= 0 ? "+" : ""}${plate.trend_15m.toFixed(1)}°C` : "--"}</strong>
+              15m: <strong>{plate.trend_15m !== null ? `${plate.trend_15m >= 0 ? "+" : ""}${plate.trend_15m.toFixed(1)}${tempSymbol}` : "--"}</strong>
             </div>
           </div>
         ))}

frontend/components/dashboard/scan-terminal/TemperatureStatsBars.tsx

@@ -7,6 +7,7 @@ export function TemperatureStatsBars({
   isEn,
   compact,
   timeframe,
+  tempSymbol,
   runwayHeaderLabel,
   metarHeaderLabel,
   runwayHighLabel,
@@ -27,6 +28,7 @@ export function TemperatureStatsBars({
   isEn: boolean;
   compact: boolean;
   timeframe: string;
+  tempSymbol: string;
   runwayHeaderLabel: string;
   metarHeaderLabel: string;
   runwayHighLabel: string;
@@ -51,18 +53,18 @@ export function TemperatureStatsBars({
           <div className="flex items-center gap-4 text-[11px]">
             <span className="font-semibold text-slate-500">
               {isEn ? "Runway" : runwayHeaderLabel}:{" "}
-              <strong className="text-[#009688] font-mono">{temp(displayRunwayTemp)}</strong>
+              <strong className="text-[#009688] font-mono">{temp(displayRunwayTemp, tempSymbol)}</strong>
             </span>
             <span className="text-slate-300">|</span>
             <span className="font-semibold text-slate-500">
               {isEn ? "METAR" : (isShenzhen ? "当日最高" : metarHeaderLabel)}:{" "}
-              <strong className="text-blue-600 font-mono">{temp(observedHighMetar)}</strong>
+              <strong className="text-blue-600 font-mono">{temp(observedHighMetar, tempSymbol)}</strong>
             </span>
           </div>
         ) : (
           <div className="flex items-center gap-4 text-[11px]">
             <span className="font-semibold text-slate-500">
-              DEB: <strong className="text-orange-600 font-mono">{temp(debVal)}</strong>
+              DEB: <strong className="text-orange-600 font-mono">{temp(debVal, tempSymbol)}</strong>
             </span>
             {modelMin !== null && modelMax !== null && (
               <>
@@ -70,7 +72,7 @@ export function TemperatureStatsBars({
                 <span className="font-semibold text-slate-500">
                   {isEn ? "Models" : "多模型"}:{" "}
                   <strong className="text-slate-700 font-mono">
-                    {temp(modelMin)} - {temp(modelMax)}
+                    {temp(modelMin, tempSymbol)} - {temp(modelMax, tempSymbol)}
                   </strong>
                 </span>
               </>
@@ -94,7 +96,7 @@ export function TemperatureStatsBars({
                 {isEn ? "Runway Live (1m)" : `${runwayHeaderLabel}`}
               </span>
               <span className="text-2xl font-bold font-mono text-[#009688] mt-1">
-                {temp(displayRunwayTemp)}
+                {temp(displayRunwayTemp, tempSymbol)}
               </span>
             </div>
             <div className="flex flex-col">
@@ -102,7 +104,7 @@ export function TemperatureStatsBars({
                 {isEn ? "METAR Settlement · Daily High" : `${metarHeaderLabel} · 当日最高`}
               </span>
               <span className="text-2xl font-bold font-mono text-blue-600 mt-1">
-                {temp(observedHighMetar)}
+                {temp(observedHighMetar, tempSymbol)}
               </span>
             </div>
           </div>
@@ -113,7 +115,7 @@ export function TemperatureStatsBars({
                 DEB Max
               </span>
               <span className="text-2xl font-bold font-mono text-orange-600 mt-1">
-                {temp(debVal)}
+                {temp(debVal, tempSymbol)}
               </span>
             </div>
             <div className="flex flex-col">
@@ -121,7 +123,7 @@ export function TemperatureStatsBars({
                 {isEn ? "Model Range" : "多模型区间"}
               </span>
               <span className="text-2xl font-bold font-mono text-slate-700 mt-1">
-                {modelMin !== null && modelMax !== null ? `${temp(modelMin)} - ${temp(modelMax)}` : "--"}
+                {modelMin !== null && modelMax !== null ? `${temp(modelMin, tempSymbol)} - ${temp(modelMax, tempSymbol)}` : "--"}
               </span>
             </div>
           </div>
@@ -132,13 +134,13 @@ export function TemperatureStatsBars({
             {isEn ? "Daily Peak" : "当日最高气温"}
           </span>
           <div className="mt-1 flex items-center gap-2 text-xs font-mono text-slate-600">
-            <span>{isEn ? "Runway" : runwayHighLabel}: <strong className="text-[#009688]">{temp(observedHighRunway)}</strong></span>
+            <span>{isEn ? "Runway" : runwayHighLabel}: <strong className="text-[#009688]">{temp(observedHighRunway, tempSymbol)}</strong></span>
             <span>|</span>
-            <span>{isEn ? "METAR" : metarHighLabel}: <strong className="text-blue-600">{temp(observedHighMetar)}</strong></span>
+            <span>{isEn ? "METAR" : metarHighLabel}: <strong className="text-blue-600">{temp(observedHighMetar, tempSymbol)}</strong></span>
             {wundergroundDailyHigh !== null && (
               <>
                 <span>|</span>
-                <span>WU: <strong className="text-purple-600">{temp(wundergroundDailyHigh)}</strong></span>
+                <span>WU: <strong className="text-purple-600">{temp(wundergroundDailyHigh, tempSymbol)}</strong></span>
               </>
             )}
           </div>
@@ -152,7 +154,7 @@ export function TemperatureStatsBars({
               {isEn ? "Model Range" : "模型区间"}
             </span>
             <strong className="text-slate-800 font-bold">
-              {modelMin !== null && modelMax !== null ? `${temp(modelMin)} - ${temp(modelMax)}` : "--"}
+              {modelMin !== null && modelMax !== null ? `${temp(modelMin, tempSymbol)} - ${temp(modelMax, tempSymbol)}` : "--"}
             </strong>
           </div>
           <div className="flex flex-col gap-0.5">
@@ -160,7 +162,7 @@ export function TemperatureStatsBars({
               DEB
             </span>
             <strong className="text-blue-600 font-bold">
-              {temp(debVal)}
+              {temp(debVal, tempSymbol)}
             </strong>
           </div>
           <div className="flex flex-col gap-0.5">
@@ -168,7 +170,7 @@ export function TemperatureStatsBars({
               {isEn ? "Spread" : "分歧"}
             </span>
             <strong className={clsx("font-bold", spreadLabel === "高分歧" ? "text-amber-600" : "text-slate-600")}>
-              {spread !== null ? `${spread.toFixed(1)}°C` : "--"}
+              {spread !== null ? `${spread.toFixed(1)}${tempSymbol}` : "--"}
               {spreadLabel && ` · ${isEn ? spreadLabelEn : spreadLabel}`}
             </strong>
           </div>

frontend/components/dashboard/scan-terminal/TemperatureTooltipContent.tsx

@@ -31,12 +31,14 @@ export function TemperatureTooltipContent({
   payload,
   data,
   series,
+  tempSymbol = "°C",
 }: {
   active?: boolean;
   label?: string | number;
   payload?: ReadonlyArray<{ payload?: Record<string, any> }>;
   data: Array<Record<string, any>>;
   series: TooltipSeries[];
+  tempSymbol?: string;
 }) {
   if (!active || !payload?.length || !series.length) return null;
   const activePoint = payload[0]?.payload || {};
@@ -60,7 +62,7 @@ export function TemperatureTooltipContent({
               <span className="h-2 w-2 rounded-full" style={{ backgroundColor: item.color }} />
               <span className="font-semibold">{item.label}</span>
             </span>
-            <strong className="font-mono text-slate-900">{item.value.toFixed(2)}°</strong>
+            <strong className="font-mono text-slate-900">{item.value.toFixed(2)}{tempSymbol}</strong>
           </div>
         ))}
       </div>

frontend/components/dashboard/scan-terminal/__tests__/refreshCadencePolicy.test.ts

@@ -6,12 +6,23 @@ import {
 } from "@/lib/refresh-policy";
 import { scanTerminalQueryPolicy } from "@/components/dashboard/scan-terminal/scan-terminal-client";
 import { __shouldPollLiveChartForTest } from "@/components/dashboard/scan-terminal/LiveTemperatureThresholdChart";
+import {
+  MAX_HOURLY_DETAIL_CONCURRENT_REQUESTS,
+  __resetHourlyDetailRequestQueueForTest,
+  __runQueuedHourlyDetailRequestForTest,
+} from "@/components/dashboard/scan-terminal/temperature-chart-logic";
 
 function assert(condition: unknown, message: string) {
   if (!condition) throw new Error(message);
 }
 
-export function runTests() {
+async function flushMicrotasks() {
+  for (let i = 0; i < 8; i += 1) {
+    await Promise.resolve();
+  }
+}
+
+export async function runTests() {
   assert(DASHBOARD_REFRESH_POLICY_MS.observation === 60_000, "observation layer should refresh every 60 seconds");
   assert(DASHBOARD_REFRESH_POLICY_MS.scanRows === 5 * 60_000, "region/city rows should refresh every 5 minutes");
   assert(DASHBOARD_REFRESH_POLICY_MS.marketOverview === 10 * 60_000, "market overview should refresh every 10 minutes");
@@ -68,4 +79,55 @@ export function runTests() {
       chartSource.includes("setHourly(seedHourlyForecastFromRow(row))"),
     "terminal charts should render from row data immediately and dedupe concurrent city detail requests",
   );
+
+  __resetHourlyDetailRequestQueueForTest();
+  let activeRequests = 0;
+  let maxActiveRequests = 0;
+  let startedRequests = 0;
+  const releases: Array<(() => void) | undefined> = [];
+  const requestCount = MAX_HOURLY_DETAIL_CONCURRENT_REQUESTS + 3;
+
+  const requests = Array.from({ length: requestCount }, (_, index) =>
+    __runQueuedHourlyDetailRequestForTest(
+      () =>
+        new Promise<number>((resolve) => {
+          startedRequests += 1;
+          activeRequests += 1;
+          maxActiveRequests = Math.max(maxActiveRequests, activeRequests);
+          releases[index] = () => {
+            activeRequests -= 1;
+            resolve(index);
+          };
+        }),
+    ),
+  );
+
+  await flushMicrotasks();
+  assert(
+    startedRequests === MAX_HOURLY_DETAIL_CONCURRENT_REQUESTS,
+    "city detail queue should start only the configured number of concurrent requests",
+  );
+  assert(
+    maxActiveRequests === MAX_HOURLY_DETAIL_CONCURRENT_REQUESTS,
+    "city detail queue must cap simultaneous full-detail requests",
+  );
+
+  releases[0]?.();
+  await flushMicrotasks();
+  assert(
+    startedRequests === MAX_HOURLY_DETAIL_CONCURRENT_REQUESTS + 1,
+    "city detail queue should start the next pending request when one active request finishes",
+  );
+
+  for (let index = 1; index < requestCount; index += 1) {
+    await flushMicrotasks();
+    assert(Boolean(releases[index]), `city detail queue should eventually start queued request #${index}`);
+    releases[index]?.();
+  }
+  const results = await Promise.all(requests);
+  assert(
+    results.length === requestCount && results.every((value, index) => value === index),
+    "city detail queue should resolve every queued request in order",
+  );
+  __resetHourlyDetailRequestQueueForTest();
 }

frontend/components/dashboard/scan-terminal/__tests__/ssePatchArchitecture.test.ts

@@ -91,12 +91,16 @@ export function runTests() {
   const chartStatsPath = path.join(process.cwd(), "components", "dashboard", "scan-terminal", "TemperatureStatsBars.tsx");
   const chartRunwayPath = path.join(process.cwd(), "components", "dashboard", "scan-terminal", "TemperatureRunwayDetails.tsx");
   const chartTooltipPath = path.join(process.cwd(), "components", "dashboard", "scan-terminal", "TemperatureTooltipContent.tsx");
+  const chartSummaryPath = path.join(process.cwd(), "components", "dashboard", "scan-terminal", "ModelCurvesSummary.tsx");
   assert(fs.existsSync(chartCanvasPath), "temperature chart Recharts canvas must live in TemperatureChartCanvas.tsx");
   assert(fs.existsSync(chartStatsPath), "temperature chart stat bars must live in TemperatureStatsBars.tsx");
   assert(fs.existsSync(chartRunwayPath), "temperature chart runway detail panel must live in TemperatureRunwayDetails.tsx");
   assert(fs.existsSync(chartTooltipPath), "temperature chart tooltip must live in TemperatureTooltipContent.tsx");
+  assert(fs.existsSync(chartSummaryPath), "temperature chart model summary must live in ModelCurvesSummary.tsx");
   const chartCanvas = fs.readFileSync(chartCanvasPath, "utf8");
   const chartTooltip = fs.readFileSync(chartTooltipPath, "utf8");
+  const chartRunway = fs.readFileSync(chartRunwayPath, "utf8");
+  const chartSummary = fs.readFileSync(chartSummaryPath, "utf8");
   const chartLogicPath = path.join(process.cwd(), "components", "dashboard", "scan-terminal", "temperature-chart-logic.ts");
   assert(fs.existsSync(chartLogicPath), "temperature chart pure data logic must live in temperature-chart-logic.ts");
   const chartLogic = fs.readFileSync(chartLogicPath, "utf8");
@@ -112,6 +116,18 @@ export function runTests() {
   assert(chart.includes("TemperatureChartCanvas"), "temperature chart shell must compose the extracted chart canvas");
   assert(chart.includes("TemperatureStatsBars"), "temperature chart shell must compose the extracted stat bars");
   assert(chart.includes("TemperatureRunwayDetails"), "temperature chart shell must compose the extracted runway panel");
+  assert(chart.includes("tempSymbol={row?.temp_symbol || \"°C\"}"), "temperature chart shell must pass the city temperature unit into stat bars");
+  assert(chart.includes("<TemperatureRunwayDetails") && chart.includes("tempSymbol={row?.temp_symbol || \"°C\"}"), "temperature chart shell must pass the city unit into runway details");
+  assert(chart.includes("<ModelCurvesSummary") && chart.includes("tempSymbol={row?.temp_symbol || \"°C\"}"), "temperature chart shell must pass the city unit into model summaries");
+  const chartStats = fs.readFileSync(chartStatsPath, "utf8");
+  assert(chartStats.includes("tempSymbol"), "temperature stat bars must accept the city temperature unit");
+  assert(chartStats.includes("temp(displayRunwayTemp, tempSymbol)"), "temperature stat bars must render live observations with the city unit");
+  assert(chartRunway.includes("tempSymbol") && !chartRunway.includes("}°C`"), "runway detail rows must render values with the city unit");
+  assert(chartSummary.includes("tempSymbol") && chartSummary.includes("temp(stats.latest, tempSymbol)"), "model curve summaries must render values with the city unit");
+  assert(chartCanvas.includes("const tempSymbol = row?.temp_symbol || \"°C\""), "temperature chart canvas must derive the city unit from the row");
+  assert(chartCanvas.includes("tempSymbol={tempSymbol}"), "temperature chart canvas must pass the city unit into tooltips");
+  assert(chartCanvas.includes("tickFormatter={(v) => `${Number(v).toFixed(0)}${tempSymbol}`}"), "temperature y-axis ticks must include °C/°F instead of a bare degree mark");
+  assert(chartTooltip.includes("tempSymbol"), "temperature tooltip must accept the city temperature unit");
   assert(!chart.includes("from \"recharts\""), "LiveTemperatureThresholdChart.tsx must not import Recharts directly");
   assert(!chart.includes("function TemperatureTooltipContent"), "LiveTemperatureThresholdChart.tsx must not define tooltip content inline");
   assert(chartCanvas.includes("TemperatureTooltipContent"), "temperature chart canvas must use a custom tooltip content component");

frontend/components/dashboard/scan-terminal/temperature-chart-logic.ts

@@ -203,6 +203,9 @@ const MAX_OBS_POINTS = 1440;
 const HOURLY_CACHE_TTL_MS = DASHBOARD_REFRESH_POLICY_MS.metar;
 const _hourlyCache = new Map<string, { ts: number; data: HourlyForecast }>();
 const _hourlyRequestCache = new Map<string, Promise<HourlyForecast>>();
+const MAX_HOURLY_DETAIL_CONCURRENT_REQUESTS = 3;
+let _hourlyActiveDetailRequests = 0;
+const _hourlyDetailRequestQueue: Array<() => void> = [];
 const RUNWAY_LINE_COLORS = ["#00897b", "#d97706", "#7c3aed", "#0891b2", "#ea580c", "#64748b"];
 
 const SESSION_CACHE_PREFIX = "polyweather_city_detail_v1:";
@@ -231,6 +234,34 @@ function writeSessionCache(city: string, data: HourlyForecast) {
   } catch {}
 }
 
+function drainHourlyDetailRequestQueue() {
+  while (
+    _hourlyActiveDetailRequests < MAX_HOURLY_DETAIL_CONCURRENT_REQUESTS &&
+    _hourlyDetailRequestQueue.length > 0
+  ) {
+    const start = _hourlyDetailRequestQueue.shift();
+    if (start) start();
+  }
+}
+
+function runQueuedHourlyDetailRequest<T>(task: () => Promise<T>): Promise<T> {
+  return new Promise<T>((resolve, reject) => {
+    const start = () => {
+      _hourlyActiveDetailRequests += 1;
+      Promise.resolve()
+        .then(task)
+        .then(resolve, reject)
+        .finally(() => {
+          _hourlyActiveDetailRequests = Math.max(0, _hourlyActiveDetailRequests - 1);
+          drainHourlyDetailRequestQueue();
+        });
+    };
+
+    _hourlyDetailRequestQueue.push(start);
+    drainHourlyDetailRequestQueue();
+  });
+}
+
 export function clearCityDetailCache() {
   _hourlyCache.clear();
   _hourlyRequestCache.clear();
@@ -246,6 +277,13 @@ export function clearCityDetailCache() {
   }
 }
 
+function __resetHourlyDetailRequestQueueForTest() {
+  _hourlyActiveDetailRequests = 0;
+  _hourlyDetailRequestQueue.length = 0;
+}
+
+const __runQueuedHourlyDetailRequestForTest = runQueuedHourlyDetailRequest;
+
 function validNumber(value: unknown): number | null {
   return typeof value === "number" && Number.isFinite(value) ? value : null;
 }
@@ -619,20 +657,22 @@ async function fetchHourlyForecastForCity(
   const pending = _hourlyRequestCache.get(requestKey);
   if (pending) return pending;
 
-  const request = fetch(`/api/city/${encodeURIComponent(city)}/detail?depth=full&force_refresh=false&resolution=${resParam}`, {
+  const request = runQueuedHourlyDetailRequest(() =>
-    headers: { Accept: "application/json" },
+    fetch(`/api/city/${encodeURIComponent(city)}/detail?depth=full&force_refresh=false&resolution=${resParam}`, {
-  })
+      headers: { Accept: "application/json" },
-    .then(async (res) => {
-      if (!res.ok) return null;
-      return res.json() as Promise<CityDetail>;
-    })
-    .then((json) => {
-      const data = parseHourlyForecastFromCityDetail(json);
-      if (!data) return null;
-      _hourlyCache.set(cacheKey, { ts: Date.now(), data });
-      writeSessionCache(cacheKey, data);
-      return data;
     })
+      .then(async (res) => {
+        if (!res.ok) return null;
+        return res.json() as Promise<CityDetail>;
+      })
+      .then((json) => {
+        const data = parseHourlyForecastFromCityDetail(json);
+        if (!data) return null;
+        _hourlyCache.set(cacheKey, { ts: Date.now(), data });
+        writeSessionCache(cacheKey, data);
+        return data;
+      }),
+  )
     .finally(() => {
       _hourlyRequestCache.delete(requestKey);
     });
@@ -1597,8 +1637,11 @@ function binObservationsToSlots(
 }
 
 export {
+  MAX_HOURLY_DETAIL_CONCURRENT_REQUESTS,
   HOURLY_CACHE_TTL_MS,
   _hourlyCache,
+  __resetHourlyDetailRequestQueueForTest,
+  __runQueuedHourlyDetailRequestForTest,
   buildChartDomain,
   buildFullDayChartData,
   getDebPeakWindowRange,

src/data_collection/country_networks.py

@@ -32,6 +32,15 @@ def _safe_float(value: Any) -> Optional[float]:
         return None
 
 
+def _display_temp_from_c(temp_c: Any, use_fahrenheit: bool) -> Optional[float]:
+    numeric = _safe_float(temp_c)
+    if numeric is None:
+        return None
+    if use_fahrenheit:
+        return round(numeric * 9.0 / 5.0 + 32.0, 1)
+    return round(numeric, 1)
+
+
 def _parse_obs_datetime(
     value: Any,
     epoch_value: Any = None,
@@ -248,11 +257,18 @@ def _airport_primary_from_raw(city: str, raw: Dict[str, Any]) -> Dict[str, Any]:
 
     # High-frequency realtime sources take priority over plain METAR.
     madis = raw.get("madis_hfmetar_current") or {}
-    if madis.get("temp_c") is not None:
+    madis_temp_c = _safe_float(madis.get("temp_c"))
+    madis_temp = _safe_float(madis.get("temp"))
+    if madis_temp is None and madis_temp_c is not None:
+        madis_temp = _display_temp_from_c(
+            madis_temp_c,
+            bool(meta.get("use_fahrenheit")),
+        )
+    if madis_temp is not None:
         return _normalize_station_row(
             station_code=meta.get("icao") or madis.get("icao"),
             station_label=meta.get("airport_name") or meta.get("icao"),
-            temp=madis["temp_c"],
+            temp=madis_temp,
             obs_time=madis.get("obs_time") or metar.get("observation_time"),
             source_code="madis_hfmetar",
             source_label="NOAA MADIS",
@@ -260,6 +276,8 @@ def _airport_primary_from_raw(city: str, raw: Dict[str, Any]) -> Dict[str, Any]:
             is_airport_station=True,
             is_settlement_anchor=False,
             extra={
+                "temp_c": madis_temp_c,
+                "unit": "fahrenheit" if bool(meta.get("use_fahrenheit")) else "celsius",
                 "max_so_far": _safe_float(current.get("max_temp_so_far")),
                 "max_temp_time": current.get("max_temp_time"),
                 "obs_age_min": None,

src/data_collection/weather_sources.py

@@ -925,6 +925,16 @@ class WeatherDataCollector(OpenMeteoCacheMixin, SettlementSourceMixin, MetarSour
     def _uses_fahrenheit(self, city_lower: str) -> bool:
         return city_lower in self.US_CITIES
 
+    @staticmethod
+    def _display_temp_from_c(temp_c: Any, use_fahrenheit: bool) -> Optional[float]:
+        try:
+            numeric = float(temp_c)
+        except (TypeError, ValueError):
+            return None
+        if use_fahrenheit:
+            return round(numeric * 9.0 / 5.0 + 32.0, 1)
+        return round(numeric, 1)
+
     def _supports_aviationweather(self, city_lower: str) -> bool:
         city_meta = self.CITY_REGISTRY.get(str(city_lower or "").strip().lower(), {}) or {}
         settlement_source = str(city_meta.get("settlement_source") or "").strip().lower()
@@ -1451,7 +1461,7 @@ class WeatherDataCollector(OpenMeteoCacheMixin, SettlementSourceMixin, MetarSour
             logger.warning("AMSC AWOS attach failed city={}: {}", city_lower, exc)
 
     def _attach_madis_hfmetar_data(
-        self, results: Dict, city_lower: str
+        self, results: Dict, city_lower: str, use_fahrenheit: bool
     ) -> None:
         """Fetch MADIS HFMETAR data and attach matching US station observations."""
         # Only run for US cities (ICAO starts with K)
@@ -1476,19 +1486,33 @@ class WeatherDataCollector(OpenMeteoCacheMixin, SettlementSourceMixin, MetarSour
         # Find this city's station in the MADIS results
         for obs in obs_list:
             if obs["icao"] == icao:
+                temp_c = self._display_temp_from_c(obs.get("temp_c"), False)
+                display_temp = self._display_temp_from_c(
+                    temp_c,
+                    use_fahrenheit,
+                )
+                if temp_c is None or display_temp is None:
+                    continue
+                display_unit = "fahrenheit" if use_fahrenheit else "celsius"
                 # Inject into results so it flows through to airport_primary
-                results["madis_hfmetar_current"] = obs
+                results["madis_hfmetar_current"] = {
+                    **obs,
+                    "temp_c": temp_c,
+                    "temp": display_temp,
+                    "unit": display_unit,
+                }
                 self._emit_temperature_patch_if_changed(
                     city_lower,
-                    obs.get("temp_c"),
+                    display_temp,
                     obs.get("obs_time"),
                     source="madis_hfmetar",
+                    extra={"temp_c": temp_c, "unit": display_unit},
                 )
                 try:
                     DBManager().append_airport_obs(
                         icao=icao,
                         city=city_lower,
-                        temp_c=obs["temp_c"],
+                        temp_c=temp_c,
                         wind_kt=obs.get("wind_kt"),
                         pressure_hpa=obs.get("pressure_hpa"),
                         obs_time=obs["obs_time"] or datetime.now().isoformat(),
@@ -1686,7 +1710,7 @@ class WeatherDataCollector(OpenMeteoCacheMixin, SettlementSourceMixin, MetarSour
                 )
                 self._attach_korean_amos_data(results, city_lower, use_fahrenheit)
                 self._attach_china_amsc_awos_data(results, city_lower, use_fahrenheit)
-                self._attach_madis_hfmetar_data(results, city_lower)
+                self._attach_madis_hfmetar_data(results, city_lower, use_fahrenheit)
                 self._attach_singapore_mss_data(results, city_lower)
                 self._attach_israel_ims_data(results, city_lower)
                 self._attach_saudi_ncm_data(results, city_lower)
@@ -1738,7 +1762,7 @@ class WeatherDataCollector(OpenMeteoCacheMixin, SettlementSourceMixin, MetarSour
                 )
                 self._attach_korean_amos_data(results, city_lower, use_fahrenheit)
                 self._attach_china_amsc_awos_data(results, city_lower, use_fahrenheit)
-                self._attach_madis_hfmetar_data(results, city_lower)
+                self._attach_madis_hfmetar_data(results, city_lower, use_fahrenheit)
                 self._attach_singapore_mss_data(results, city_lower)
                 self._attach_israel_ims_data(results, city_lower)
                 self._attach_saudi_ncm_data(results, city_lower)

tests/test_country_networks.py

@@ -344,6 +344,33 @@ def test_moscow_provider_uses_realtime_metar_cluster_not_station_archive_rows():
     assert snapshot["official_nearby"][0]["is_airport_station"] is True
 
 
+def test_us_madis_airport_primary_uses_city_display_unit():
+    raw = {
+        "madis_hfmetar_current": {
+            "icao": "KHOU",
+            "temp_c": 19.4,
+            "temp": 66.9,
+            "obs_time": "2026-05-27T17:00:00+00:00",
+            "wind_kt": 8.0,
+        },
+        "metar": {
+            "observation_time": "2026-05-27T17:00:00+00:00",
+            "current": {
+                "temp": 66.9,
+                "max_temp_so_far": 84.9,
+            },
+        },
+    }
+
+    snapshot = build_country_network_snapshot("houston", raw)
+    airport_primary = snapshot["airport_primary_current"]
+
+    assert airport_primary["source_code"] == "madis_hfmetar"
+    assert airport_primary["source_label"] == "NOAA MADIS"
+    assert airport_primary["temp"] == 66.9
+    assert airport_primary["temp_c"] == 19.4
+
+
 def test_city_detail_payload_exposes_airport_and_official_network_layers():
     payload = _build_city_detail_payload(
         {

tests/test_multi_model_sources.py

@@ -53,6 +53,60 @@ def test_multi_model_order_includes_legacy_and_new_sources():
     assert "jma_seamless" in OPEN_METEO_MULTI_MODEL_ORDER
 
 
+def test_madis_patch_uses_city_display_unit_for_us(monkeypatch):
+    collector = WeatherDataCollector({})
+    emitted = []
+    stored = []
+
+    monkeypatch.setattr(
+        collector,
+        "fetch_madis_hfmetar",
+        lambda: [
+            {
+                "icao": "KHOU",
+                "temp_c": 19.4,
+                "obs_time": "2026-05-27T17:00:00+00:00",
+                "wind_kt": 8.0,
+            }
+        ],
+    )
+    monkeypatch.setattr(
+        collector,
+        "_emit_temperature_patch_if_changed",
+        lambda city, temp, obs_time=None, **kwargs: emitted.append(
+            {
+                "city": city,
+                "temp": temp,
+                "obs_time": obs_time,
+                **kwargs,
+            }
+        ),
+    )
+
+    class FakeDBManager:
+        def append_airport_obs(self, **kwargs):
+            stored.append(kwargs)
+
+    monkeypatch.setattr(
+        "src.data_collection.weather_sources.DBManager",
+        lambda: FakeDBManager(),
+    )
+
+    results = {}
+    collector._attach_madis_hfmetar_data(
+        results,
+        "houston",
+        use_fahrenheit=True,
+    )
+
+    assert results["madis_hfmetar_current"]["temp"] == 66.9
+    assert results["madis_hfmetar_current"]["temp_c"] == 19.4
+    assert emitted[0]["temp"] == 66.9
+    assert emitted[0]["extra"]["temp_c"] == 19.4
+    assert emitted[0]["extra"]["unit"] == "fahrenheit"
+    assert stored[0]["temp_c"] == 19.4
+
+
 def test_fetch_all_sources_prioritizes_multi_model_before_forecast(monkeypatch, tmp_path):
     monkeypatch.setenv("OPEN_METEO_DISK_CACHE_PATH", str(tmp_path / "om-cache.json"))
     collector = WeatherDataCollector({})