diff --git a/frontend/components/dashboard/scan-terminal/TemperatureStatsBars.tsx b/frontend/components/dashboard/scan-terminal/TemperatureStatsBars.tsx
index 53e02919..a5082911 100644
--- a/frontend/components/dashboard/scan-terminal/TemperatureStatsBars.tsx
+++ b/frontend/components/dashboard/scan-terminal/TemperatureStatsBars.tsx
@@ -43,6 +43,19 @@ type DebQuality = {
   recommendation?: string | null;
   recent_hit_rate?: number | null;
   recent_samples?: number | null;
+  ensemble_signal?: DebEnsembleSignal | null;
+};
+
+type DebEnsembleSignal = {
+  available?: boolean;
+  stance?: string | null;
+  label_zh?: string | null;
+  label_en?: string | null;
+  reason_zh?: string | null;
+  reason_en?: string | null;
+  spread?: number | null;
+  deb_distance?: number | null;
+  confidence_delta?: number | null;
 };
 
 function debQualityLabel(quality: DebQuality | null | undefined, isEn: boolean) {
@@ -55,6 +68,9 @@ function debQualityLabel(quality: DebQuality | null | undefined, isEn: boolean)
 }
 
 function debQualityClass(quality: DebQuality | null | undefined) {
+  const stance = quality?.ensemble_signal?.available ? quality.ensemble_signal.stance : null;
+  if (stance === "caution") return "border-amber-300 bg-amber-50 text-amber-700";
+  if (stance === "supporting") return "border-emerald-200 bg-emerald-50 text-emerald-700";
   const tier = quality?.quality_tier;
   if (tier === "high") return "border-emerald-200 bg-emerald-50 text-emerald-700";
   if (tier === "medium") return "border-amber-200 bg-amber-50 text-amber-700";
@@ -62,22 +78,46 @@ function debQualityClass(quality: DebQuality | null | undefined) {
   return "border-slate-200 bg-slate-50 text-slate-500";
 }
 
-function DebQualityBadge({ quality, isEn }: { quality?: DebQuality | null; isEn: boolean }) {
+function debEnsembleShortLabel(signal: DebEnsembleSignal | null | undefined, isEn: boolean) {
+  if (!signal?.available) return "";
+  if (signal.stance === "supporting") return isEn ? "Ens+" : "集+";
+  if (signal.stance === "caution") return isEn ? "Ens!" : "集警";
+  return "";
+}
+
+function debQualityTitle(quality: DebQuality | null | undefined, isEn: boolean) {
   const label = debQualityLabel(quality, isEn);
-  if (!label) return null;
   const hitRate = quality?.recent_hit_rate;
   const samples = quality?.recent_samples;
+  const ensemble = quality?.ensemble_signal;
   const titleParts = [
-    isEn ? `DEB recommendation: ${label}` : `DEB 建议：${label}`,
+    label ? (isEn ? `DEB recommendation: ${label}` : `DEB 建议：${label}`) : null,
     hitRate == null ? null : `${hitRate.toFixed(0)}%`,
     samples == null ? null : `n=${samples}`,
+    ensemble?.available
+      ? `${isEn ? ensemble.label_en || "Ensemble" : ensemble.label_zh || "集合"}: ${
+          isEn ? ensemble.reason_en || "" : ensemble.reason_zh || ""
+        }`
+      : null,
   ].filter(Boolean);
+  return titleParts.join(" · ");
+}
+
+function DebQualityBadge({ quality, isEn }: { quality?: DebQuality | null; isEn: boolean }) {
+  const label = debQualityLabel(quality, isEn);
+  const ensembleLabel = debEnsembleShortLabel(quality?.ensemble_signal, isEn);
+  if (!label && !ensembleLabel) return null;
   return (
     <span
       className={clsx("ml-1.5 inline-flex items-center rounded border px-1.5 py-0.5 text-[9px] font-black uppercase leading-none", debQualityClass(quality))}
-      title={titleParts.join(" · ")}
+      title={debQualityTitle(quality, isEn)}
     >
-      {label}
+      {label || "DEB"}
+      {ensembleLabel && (
+        <span className="ml-1 border-l border-current/30 pl-1">
+          {ensembleLabel}
+        </span>
+      )}
     </span>
   );
 }
@@ -313,3 +353,6 @@ export function TemperatureStatsBars({
 
 export const __buildTemperatureStatsLabelsForTest = buildStatsLabels;
 export const __buildDebQualityLabelForTest = debQualityLabel;
+export const __buildDebQualityClassForTest = debQualityClass;
+export const __buildDebQualityTitleForTest = debQualityTitle;
+export const __buildDebEnsembleLabelForTest = debEnsembleShortLabel;
diff --git a/frontend/components/dashboard/scan-terminal/__tests__/temperatureStatsLabels.test.ts b/frontend/components/dashboard/scan-terminal/__tests__/temperatureStatsLabels.test.ts
index c9ca05dc..27c0ae48 100644
--- a/frontend/components/dashboard/scan-terminal/__tests__/temperatureStatsLabels.test.ts
+++ b/frontend/components/dashboard/scan-terminal/__tests__/temperatureStatsLabels.test.ts
@@ -1,4 +1,10 @@
-import { __buildDebQualityLabelForTest, __buildTemperatureStatsLabelsForTest } from "@/components/dashboard/scan-terminal/TemperatureStatsBars";
+import {
+  __buildDebEnsembleLabelForTest,
+  __buildDebQualityClassForTest,
+  __buildDebQualityLabelForTest,
+  __buildDebQualityTitleForTest,
+  __buildTemperatureStatsLabelsForTest,
+} from "@/components/dashboard/scan-terminal/TemperatureStatsBars";
 import { temp } from "@/components/dashboard/scan-terminal/utils";
 
 function assert(condition: unknown, message: string) {
@@ -71,4 +77,35 @@ export function runTests() {
     __buildDebQualityLabelForTest({ recommendation: "insufficient" }, false) === "样本少",
     "thin-sample DEB should render a Chinese low-sample label",
   );
+  const supportingSignal = {
+    available: true,
+    stance: "supporting",
+    label_zh: "集合支撑",
+    label_en: "Ensemble support",
+    reason_zh: "集合区间较窄",
+    reason_en: "Ensemble spread is tight",
+  };
+  assert(
+    __buildDebEnsembleLabelForTest(supportingSignal, false) === "集+",
+    "supporting ensemble signal should render a compact Chinese marker",
+  );
+  assert(
+    __buildDebEnsembleLabelForTest({ ...supportingSignal, stance: "caution" }, true) === "Ens!",
+    "caution ensemble signal should render a compact English marker",
+  );
+  assert(
+    __buildDebQualityClassForTest({
+      recommendation: "primary",
+      quality_tier: "high",
+      ensemble_signal: { ...supportingSignal, stance: "caution" },
+    }).includes("amber"),
+    "ensemble caution should override the DEB quality badge color",
+  );
+  assert(
+    __buildDebQualityTitleForTest(
+      { recommendation: "primary", ensemble_signal: supportingSignal },
+      false,
+    ).includes("集合支撑"),
+    "DEB badge title should include the ensemble signal reason",
+  );
 }
diff --git a/frontend/components/dashboard/scan-terminal/temperature-chart-logic.ts b/frontend/components/dashboard/scan-terminal/temperature-chart-logic.ts
index c0e866c8..42e11671 100644
--- a/frontend/components/dashboard/scan-terminal/temperature-chart-logic.ts
+++ b/frontend/components/dashboard/scan-terminal/temperature-chart-logic.ts
@@ -1605,7 +1605,16 @@ function seedRunwayPlateHistoryFromRow(
 type ChartRenderState = {
   forecastTodayHigh?: number | null;
   debPrediction?: number | null;
-  debQuality?: Pick<DebForecast, "quality_tier" | "recommendation" | "recent_hit_rate" | "recent_samples" | "recent_hits" | "recent_mae"> | null;
+  debQuality?: Pick<
+    DebForecast,
+    | "quality_tier"
+    | "recommendation"
+    | "recent_hit_rate"
+    | "recent_samples"
+    | "recent_hits"
+    | "recent_mae"
+    | "ensemble_signal"
+  > | null;
   debHourlyPath?: DebHourlyPath | null;
   localDate?: string | null;
   localTime?: string | null;
@@ -1995,6 +2004,7 @@ function parseFullChartDetailFromCityDetail(json: CityDetail | null): FullChartD
       recent_samples: json.deb.recent_samples,
       recent_hits: json.deb.recent_hits,
       recent_mae: json.deb.recent_mae,
+      ensemble_signal: json.deb.ensemble_signal,
     } : null,
     debHourlyPath: json.deb?.hourly_path || null,
     localDate: json.local_date || (json as any)?.overview?.local_date || null,
diff --git a/frontend/lib/dashboard-types.ts b/frontend/lib/dashboard-types.ts
index a5d740be..38beb91c 100644
--- a/frontend/lib/dashboard-types.ts
+++ b/frontend/lib/dashboard-types.ts
@@ -221,6 +221,21 @@ export interface DebHourlyPath {
   correction?: Record<string, unknown> | null;
 }
 
+export interface DebEnsembleSignal {
+  available?: boolean;
+  stance?: "supporting" | "neutral" | "caution" | "unavailable" | string;
+  confidence_delta?: number | null;
+  median?: number | null;
+  p10?: number | null;
+  p90?: number | null;
+  spread?: number | null;
+  deb_distance?: number | null;
+  label_zh?: string | null;
+  label_en?: string | null;
+  reason_zh?: string | null;
+  reason_en?: string | null;
+}
+
 export interface DebForecast {
   prediction: number | null;
   raw_prediction?: number | null;
@@ -239,6 +254,7 @@ export interface DebForecast {
   intraday_adjustment?: number | null;
   hourly_path?: DebHourlyPath | null;
   hourly_correction?: Record<string, unknown> | null;
+  ensemble_signal?: DebEnsembleSignal | null;
 }
 
 export interface CitySummary {
diff --git a/src/analysis/trend_engine.py b/src/analysis/trend_engine.py
index 0371c1f1..2e2b8af1 100644
--- a/src/analysis/trend_engine.py
+++ b/src/analysis/trend_engine.py
@@ -59,6 +59,116 @@ def _median(values: List[float]) -> Optional[float]:
     return (sorted_values[mid - 1] + sorted_values[mid]) / 2.0
 
 
+def _build_deb_ensemble_signal(
+    *,
+    deb_prediction: Optional[float],
+    ens_median: Optional[float],
+    ens_p10: Optional[float],
+    ens_p90: Optional[float],
+    temp_symbol: str,
+) -> Dict[str, Any]:
+    unavailable = {
+        "available": False,
+        "stance": "unavailable",
+        "confidence_delta": 0.0,
+        "median": ens_median,
+        "p10": ens_p10,
+        "p90": ens_p90,
+        "spread": None,
+        "deb_distance": None,
+        "label_zh": "集合缺失",
+        "label_en": "No ensemble",
+        "reason_zh": "集合预报数据不完整，DEB 不做 ensemble 置信度校验。",
+        "reason_en": "Ensemble data is incomplete, so DEB confidence is not ensemble-checked.",
+    }
+    if (
+        deb_prediction is None
+        or ens_median is None
+        or ens_p10 is None
+        or ens_p90 is None
+    ):
+        return unavailable
+
+    low = min(ens_p10, ens_p90)
+    high = max(ens_p10, ens_p90)
+    spread = high - low
+    deb_distance = abs(deb_prediction - ens_median)
+    scale = 1.8 if "F" in str(temp_symbol).upper() else 1.0
+    narrow_spread = 1.5 * scale
+    wide_spread = 3.5 * scale
+    aligned_gap = 0.7 * scale
+    divergent_gap = 1.5 * scale
+
+    rounded_spread = round(spread, 1)
+    rounded_distance = round(deb_distance, 1)
+    unit = temp_symbol or "°"
+
+    if spread >= wide_spread or deb_distance >= max(divergent_gap, spread * 0.45):
+        return {
+            "available": True,
+            "stance": "caution",
+            "confidence_delta": -0.12,
+            "median": round(ens_median, 1),
+            "p10": round(low, 1),
+            "p90": round(high, 1),
+            "spread": rounded_spread,
+            "deb_distance": rounded_distance,
+            "label_zh": "集合分歧",
+            "label_en": "Ensemble caution",
+            "reason_zh": (
+                f"集合区间宽度 {rounded_spread}{unit}，DEB 距集合中位数 "
+                f"{rounded_distance}{unit}，该点位应降低置信度。"
+            ),
+            "reason_en": (
+                f"Ensemble spread is {rounded_spread}{unit}; DEB is "
+                f"{rounded_distance}{unit} from the ensemble median, so confidence is reduced."
+            ),
+        }
+
+    if spread <= narrow_spread and deb_distance <= aligned_gap:
+        return {
+            "available": True,
+            "stance": "supporting",
+            "confidence_delta": 0.08,
+            "median": round(ens_median, 1),
+            "p10": round(low, 1),
+            "p90": round(high, 1),
+            "spread": rounded_spread,
+            "deb_distance": rounded_distance,
+            "label_zh": "集合支撑",
+            "label_en": "Ensemble support",
+            "reason_zh": (
+                f"集合区间较窄，DEB 仅距集合中位数 {rounded_distance}{unit}，"
+                "可作为置信度加分。"
+            ),
+            "reason_en": (
+                f"Ensemble spread is tight and DEB is only {rounded_distance}{unit} "
+                "from the ensemble median, adding confidence."
+            ),
+        }
+
+    return {
+        "available": True,
+        "stance": "neutral",
+        "confidence_delta": 0.0,
+        "median": round(ens_median, 1),
+        "p10": round(low, 1),
+        "p90": round(high, 1),
+        "spread": rounded_spread,
+        "deb_distance": rounded_distance,
+        "label_zh": "集合中性",
+        "label_en": "Ensemble neutral",
+        "reason_zh": (
+            f"集合区间宽度 {rounded_spread}{unit}，DEB 距集合中位数 "
+            f"{rounded_distance}{unit}，暂不调整置信度。"
+        ),
+        "reason_en": (
+            f"Ensemble spread is {rounded_spread}{unit}; DEB is "
+            f"{rounded_distance}{unit} from the median, so confidence is unchanged."
+        ),
+    }
+
+
 def _peak_hours_from_hourly_values(
     hourly_values: List[Tuple[str, float]],
     *,
@@ -636,6 +746,13 @@ def analyze_weather_trend(
     ens_p90 = _sf(ensemble.get("p90"))
     ens_median = _sf(ensemble.get("median"))
     ens_data = {"p10": ens_p10, "p90": ens_p90, "median": ens_median}
+    deb_ensemble_signal = _build_deb_ensemble_signal(
+        deb_prediction=deb_prediction,
+        ens_median=ens_median,
+        ens_p10=ens_p10,
+        ens_p90=ens_p90,
+        temp_symbol=temp_symbol,
+    )
 
     sigma = None
     fallback_sigma = False
@@ -648,6 +765,14 @@ def analyze_weather_trend(
         if not is_cooling:
             insights.append(msg1)
         ai_features.append(msg1)
+        if deb_ensemble_signal.get("available") and deb_prediction is not None:
+            ensemble_deb_msg = (
+                f"🧬 {deb_ensemble_signal['label_zh']}: "
+                f"{deb_ensemble_signal['reason_zh']}"
+            )
+            ai_features.append(ensemble_deb_msg)
+            if deb_ensemble_signal.get("stance") == "caution":
+                insights.append(ensemble_deb_msg)
 
         if om_today is not None:
             if om_today > ens_p90 and (
@@ -1008,6 +1133,7 @@ def analyze_weather_trend(
         "deb_bias_samples": deb_bias_samples,
         "deb_weights": deb_weights,
         "deb_quality": deb_quality,
+        "deb_ensemble_signal": deb_ensemble_signal,
         "current_forecasts": current_forecasts,
         "ens_data": ens_data,
         "forecast_miss_deg": forecast_miss_deg,
diff --git a/tests/test_trend_engine.py b/tests/test_trend_engine.py
index 8ba01deb..592aec99 100644
--- a/tests/test_trend_engine.py
+++ b/tests/test_trend_engine.py
@@ -242,6 +242,72 @@ class TestMuCalculation:
         assert sd["peak_status"] == "before"
 
 
+class TestDebEnsembleSignal:
+    @patch(
+        "src.analysis.trend_engine.calculate_deb_prediction",
+        return_value={
+            "prediction": 30.1,
+            "raw_prediction": 30.1,
+            "weights_info": "test weights",
+        },
+    )
+    @patch("src.analysis.trend_engine.get_deb_accuracy", return_value=None)
+    @patch("src.analysis.trend_engine.update_daily_record")
+    def test_narrow_ensemble_supports_aligned_deb(self, _udr, _deb_acc, _deb):
+        data = _make_weather_data(
+            cur_temp=25.0,
+            max_so_far=25.2,
+            om_today_high=30.0,
+            ens_median=30.0,
+            ens_p10=29.4,
+            ens_p90=30.6,
+            local_time="2026-03-04 10:00",
+            multi_model={"ECMWF": 30.2, "GFS": 30.0},
+        )
+
+        _, ai_context, sd = analyze_weather_trend(data, "°C", "test_city")
+
+        signal = sd["deb_ensemble_signal"]
+        assert signal["available"] is True
+        assert signal["stance"] == "supporting"
+        assert signal["confidence_delta"] > 0
+        assert signal["spread"] == 1.2
+        assert "集合支撑" in ai_context
+        assert "GEFS" not in sd["current_forecasts"]
+        assert not any("ensemble" in name.lower() for name in sd["current_forecasts"])
+
+    @patch(
+        "src.analysis.trend_engine.calculate_deb_prediction",
+        return_value={
+            "prediction": 31.0,
+            "raw_prediction": 31.0,
+            "weights_info": "test weights",
+        },
+    )
+    @patch("src.analysis.trend_engine.get_deb_accuracy", return_value=None)
+    @patch("src.analysis.trend_engine.update_daily_record")
+    def test_wide_ensemble_marks_deb_as_caution(self, _udr, _deb_acc, _deb):
+        data = _make_weather_data(
+            cur_temp=25.0,
+            max_so_far=25.2,
+            om_today_high=30.0,
+            ens_median=29.0,
+            ens_p10=24.0,
+            ens_p90=34.0,
+            local_time="2026-03-04 10:00",
+            multi_model={"ECMWF": 30.2, "GFS": 31.0},
+        )
+
+        _, ai_context, sd = analyze_weather_trend(data, "°C", "test_city")
+
+        signal = sd["deb_ensemble_signal"]
+        assert signal["available"] is True
+        assert signal["stance"] == "caution"
+        assert signal["confidence_delta"] < 0
+        assert signal["spread"] == 10.0
+        assert "集合分歧" in ai_context
+
+
 # ─── Tests: Dead Market ───
 
 class TestDeadMarket:
diff --git a/web/analysis_service.py b/web/analysis_service.py
index d4b8ca81..20cf31c3 100644
--- a/web/analysis_service.py
+++ b/web/analysis_service.py
@@ -1075,6 +1075,7 @@ def _analyze(
     probabilities_all = []
     mu = None
     dynamic_commentary = {"summary": "", "notes": []}
+    deb_ensemble_signal = {}
     try:
         _, _ai_context, sd = _trend_analyze(raw, sym, city)
 
@@ -1082,6 +1083,7 @@ def _analyze(
         probabilities = sd.get("probabilities", [])
         probabilities_all = sd.get("probabilities_all", probabilities)
         dynamic_commentary = sd.get("dynamic_commentary") or dynamic_commentary
+        deb_ensemble_signal = sd.get("deb_ensemble_signal") or {}
         trend_info["is_dead_market"] = sd.get("trend_info", {}).get("is_dead_market", False)
         trend_info["direction"] = sd.get("trend_info", {}).get("direction", trend_info.get("direction", "unknown"))
         trend_info["is_cooling"] = sd.get("trend_info", {}).get("is_cooling", False)
@@ -1630,6 +1632,7 @@ def _analyze(
             "hourly_consensus": deb_hourly_consensus,
             "hourly_path": deb_hourly_path,
             "hourly_correction": (deb_hourly_path or {}).get("correction") if isinstance(deb_hourly_path, dict) else None,
+            "ensemble_signal": deb_ensemble_signal,
             **deb_quality,
         },
         "deviation_monitor": deviation_monitor,