diff --git a/frontend/components/dashboard/scan-terminal/__tests__/stableServerRefreshPolicy.test.ts b/frontend/components/dashboard/scan-terminal/__tests__/stableServerRefreshPolicy.test.ts
index 902ccdc9..4233a917 100644
--- a/frontend/components/dashboard/scan-terminal/__tests__/stableServerRefreshPolicy.test.ts
+++ b/frontend/components/dashboard/scan-terminal/__tests__/stableServerRefreshPolicy.test.ts
@@ -20,6 +20,7 @@ export function runTests() {
     "dashboard",
     "ScanTerminalDashboard.tsx",
   );
+  const dashboardClientPath = path.join(projectRoot, "lib", "dashboard-client.ts");
   const airportEvidencePath = path.join(
     projectRoot,
     "components",
@@ -30,6 +31,7 @@ export function runTests() {
 
   const querySource = fs.readFileSync(queryPath, "utf8");
   const dashboardSource = fs.readFileSync(dashboardPath, "utf8");
+  const dashboardClientSource = fs.readFileSync(dashboardClientPath, "utf8");
   const airportEvidenceSource = fs.readFileSync(airportEvidencePath, "utf8");
 
   assert(
@@ -49,4 +51,8 @@ export function runTests() {
       !airportEvidenceSource.includes("busan:"),
     "airport evidence must only expose configured focused runways, not all runway observations",
   );
+  assert(
+    dashboardClientSource.includes('CACHE_KEY = "polyWeather_v2_chart_full_day"'),
+    "city detail cache key must be bumped so old partial chart detail caches are not reused",
+  );
 }
diff --git a/frontend/lib/dashboard-client.ts b/frontend/lib/dashboard-client.ts
index 3b542e8a..f422f674 100644
--- a/frontend/lib/dashboard-client.ts
+++ b/frontend/lib/dashboard-client.ts
@@ -15,7 +15,7 @@ import {
 } from "@/lib/backend-api";
 import { formatHttpErrorMessage } from "@/lib/http-error";
 
-const CACHE_KEY = "polyWeather_v1";
+const CACHE_KEY = "polyWeather_v2_chart_full_day";
 const CACHE_TTL_MS = 30 * 60 * 1000;
 const SCAN_TERMINAL_CLIENT_TIMEOUT_MS = 35_000;
 const CITY_DETAIL_CLIENT_TIMEOUT_MS = 35_000;