diff --git a/static/js/weather-chart.js b/static/js/weather-chart.js
index 3a144e0..c27d9da 100644
--- a/static/js/weather-chart.js
+++ b/static/js/weather-chart.js
@@ -45,7 +45,10 @@ const WeatherChart = {
 			const bucket = byTime.get(fp.date_time);
 			const h = typeof fp.lead_hours === 'number' ? fp.lead_hours : null;
 			if (h !== null && h >= 0 && h <= 3) {
-				bucket[h] = fp;
+				// 保留同一 forecast_time+lead 的最新版本（查询结果已按 issued_at DESC 排序）
+				if (bucket[h] == null) {
+					bucket[h] = fp;
+				}
 			}
 		});
 
@@ -81,6 +84,76 @@ const WeatherChart = {
 
 		if (this.chart) this.chart.destroy();
 
+		// 计算降水分类准确率（+1h/+2h/+3h）
+			const updateAccuracyPanel = () => {
+			// 仅在有历史数据（实际）时计算
+			const usedIdx = historyRainfalls
+				.map((v, idx) => ({ v, idx }))
+				.filter(x => x.v !== null)
+				.map(x => x.idx);
+			const totalHours = usedIdx.length;
+			const bucketOf = (mm) => {
+				if (mm === null || mm === undefined || isNaN(Number(mm))) return null;
+				const v = Math.max(0, Number(mm));
+				if (v < 5) return 0;
+				if (v < 10) return 1;
+				return 2;
+			};
+			const calcFor = (arrFcst) => {
+				let correct = 0;
+				usedIdx.forEach(i => {
+					const a = historyRainfalls[i];
+					const f = arrFcst[i];
+					const ba = bucketOf(a);
+					const bf = bucketOf(f);
+					if (ba !== null && bf !== null && ba === bf) correct += 1;
+				});
+				return { correct, total: totalHours };
+			};
+			const fmt = (n) => `${n.toFixed(1)}%`;
+			const elPanel = document.getElementById('accuracyPanel');
+			const elH1 = document.getElementById('accH1');
+			const elH2 = document.getElementById('accH2');
+			const elH3 = document.getElementById('accH3');
+			if (!elPanel || !elH1 || !elH2 || !elH3) return;
+			if (forecastData.length === 0 || totalHours === 0) {
+				elPanel.style.display = 'none';
+				return;
+			}
+			// 详细计算过程日志
+			try {
+				console.groupCollapsed('[准确率] 降水分档 (+1h/+2h/+3h) 计算详情');
+				console.log('时间段总小时(有实测):', totalHours);
+				const nameOf = (b) => (b===0?'[0,5)':(b===1?'[5,10)':'[10,∞)'));
+				const fv = (v) => (v===null||v===undefined||isNaN(Number(v)) ? 'NULL' : Number(v).toFixed(2));
+				usedIdx.forEach(i => {
+					const label = allLabels[i];
+					const a = historyRainfalls[i];
+					const bA = bucketOf(a);
+					const f1 = forecastRainfallsH1[i]; const b1 = bucketOf(f1);
+					const f2 = forecastRainfallsH2[i]; const b2 = bucketOf(f2);
+					const f3 = forecastRainfallsH3[i]; const b3 = bucketOf(f3);
+					const m1 = (bA!==null && b1!==null && bA===b1) ? '√' : '×';
+					const m2 = (bA!==null && b2!==null && bA===b2) ? '√' : '×';
+					const m3 = (bA!==null && b3!==null && bA===b3) ? '√' : '×';
+					console.log(
+						`${label} | 实测 ${fv(a)}mm (${bA===null?'--':nameOf(bA)}) | +1h ${fv(f1)} (${b1===null?'--':nameOf(b1)}) ${m1} | +2h ${fv(f2)} (${b2===null?'--':nameOf(b2)}) ${m2} | +3h ${fv(f3)} (${b3===null?'--':nameOf(b3)}) ${m3}`
+					);
+				});
+			} catch (e) { console.warn('准确率计算日志输出失败', e); }
+			const r1 = calcFor(forecastRainfallsH1);
+			const r2 = calcFor(forecastRainfallsH2);
+			const r3 = calcFor(forecastRainfallsH3);
+			console.log(`+1h: ${r1.correct}/${r1.total}`);
+			console.log(`+2h: ${r2.correct}/${r2.total}`);
+			console.log(`+3h: ${r3.correct}/${r3.total}`);
+			console.groupEnd();
+			elH1.textContent = r1.total > 0 ? fmt((r1.correct / r1.total) * 100) : '--';
+			elH2.textContent = r2.total > 0 ? fmt((r2.correct / r2.total) * 100) : '--';
+			elH3.textContent = r3.total > 0 ? fmt((r3.correct / r3.total) * 100) : '--';
+			elPanel.style.display = 'block';
+		};
+
 		const datasets = [
 			{
 				label: '温度 (°C) - 实测',
@@ -274,6 +347,9 @@ const WeatherChart = {
 
 		this.chart = new Chart(ctx, chartConfig);
 
+		// 更新准确率面板
+		updateAccuracyPanel();
+
 		const mode = document.getElementById('legendMode')?.value || 'combo_standard';
 		this.applyLegendMode(mode);
 	}
@@ -339,4 +415,4 @@ WeatherChart.updateAxesVisibility = function() {
 	});
 };
 
-window.WeatherChart = WeatherChart; 
\ No newline at end of file
+window.WeatherChart = WeatherChart; 
diff --git a/templates/index.html b/templates/index.html
index 90ea427..8edeb5e 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -196,6 +196,18 @@
             animation: slideDown 0.3s ease;
         }
 
+        .accuracy-panel {
+            display: none;
+            font-size: 12px;
+            color: #374151; /* 灰色文字 */
+            white-space: nowrap;
+            text-align: right;
+            margin-top: -6px;
+        }
+        .accuracy-panel .item { margin-left: 8px; }
+        .accuracy-panel .label { color: #6b7280; margin-right: 4px; }
+        .accuracy-panel .value { font-weight: 600; color: #111827; }
+
         .chart-wrapper {
             height: 500px;
             margin-bottom: 30px;
@@ -520,7 +532,6 @@
                 </div>
             </div>
 
-            <!-- 在时间范围下方增加瓦片联动控制 -->
             <div class="control-row flex items-center gap-3 flex-wrap">
                 <div class="control-group">
                     <label class="text-sm text-gray-600">叠加显示:</label>
@@ -552,6 +563,11 @@
 
         <div class="chart-container" id="chartContainer">
             <div id="stationInfoTitle" class="station-info-title"></div>
+            <div id="accuracyPanel" class="accuracy-panel">
+                <span class="item"><span class="label">+1h</span><span id="accH1" class="value">--</span></span>
+                <span class="item"><span class="label">+2h</span><span id="accH2" class="value">--</span></span>
+                <span class="item"><span class="label">+3h</span><span id="accH3" class="value">--</span></span>
+            </div>
             <div class="chart-wrapper">
                 <canvas id="combinedChart"></canvas>
             </div>