diff --git a/templates/imdroid_radar.html b/templates/imdroid_radar.html
index 5de41a8..d7d0897 100644
--- a/templates/imdroid_radar.html
+++ b/templates/imdroid_radar.html
@@ -121,6 +121,7 @@
       }
       maybeCalcSector();
       maybePlotSquare();
+      maybeCalcNearbyRain();
     }
 
     async function loadTileAt(z, y, x, dtStr) {
@@ -146,6 +147,7 @@
       }
       maybeCalcSector();
       maybePlotSquare();
+      maybeCalcNearbyRain();
     }
 
     function fmtDTLocal(dt){
@@ -272,6 +274,12 @@
         xsFan.push(gStLon); ysFan.push(gStLat);
         data.push({ type:'scatter', mode:'lines', x:xsFan, y:ysFan, line:{ color:'#FFFFFF', width:2, dash:'dash' }, fill:'toself', fillcolor:'rgba(255,255,255,0.18)', hoverinfo:'skip', showlegend:false });
       }
+      // 叠加附近5km圆
+      if (gStLat !== null && gStLon !== null) {
+        const Rm = 8000; const samples=128; const xsC=[], ysC=[];
+        for(let i=0;i<=samples;i++){ const θ=i*(360/samples); const p=destPoint(gStLat,gStLon,θ,Rm); xsC.push(p.lon); ysC.push(p.lat); }
+        data.push({ type:'scatter', mode:'lines', x:xsC, y:ysC, line:{ color:'#66CC66', width:1, dash:'dot' }, hoverinfo:'skip', showlegend:false });
+      }
       Plotly.newPlot('tile_plot', data, {
         margin:{l:36,r:8,t:8,b:90},
         xaxis:{title:{text:'经度', standoff: 12}, tickformat:'.2f', constrain:'domain', automargin:true},
@@ -366,6 +374,12 @@
           xsFan.push(gStLon); ysFan.push(gStLat);
           data.push({ type:'scatter', mode:'lines', x:xsFan, y:ysFan, line:{color:'#FFFFFF',width:2,dash:'dash'}, fill:'toself', fillcolor:'rgba(255,255,255,0.18)', hoverinfo:'skip', showlegend:false });
         }
+        // 叠加附近5km圆
+        {
+          const Rm = 8000; const samples=128; const xsC=[], ysC=[];
+          for(let i=0;i<=samples;i++){ const θ=i*(360/samples); const p=destPoint(gStLat,gStLon,θ,Rm); xsC.push(p.lon); ysC.push(p.lat); }
+          data.push({ type:'scatter', mode:'lines', x:xsC, y:ysC, line:{ color:'#66CC66', width:1, dash:'dot' }, hoverinfo:'skip', showlegend:false });
+        }
         const el=document.getElementById('squarePlot');
         const layout={ autosize:true, margin:{l:40,r:8,t:8,b:90},
           xaxis:{title:'经度', tickformat:'.2f', zeroline:false, constrain:'domain', automargin:true, range:[lonMin, lonMax]},
@@ -376,6 +390,26 @@
       }catch(e){ document.getElementById('squarePlot').innerHTML=`<div class=\"p-3 text-sm text-red-600 bg-red-50 border border-red-200 rounded\">正方形热力图渲染失败：${e.message}</div>`; }
     }
 
+    function maybeCalcNearbyRain(){
+      try{
+        const el = document.getElementById('nearbyStatus'); if(!el) return;
+        if(!gTileValues || !gXs || !gYs || gStLat===null || gStLon===null){ el.textContent=''; return; }
+        const radiusM = 8000; // 8km
+        const h=gTileValues.length, w=gTileValues[0].length;
+        let hit=false, maxDBZ=null;
+        for(let r=0;r<h && !hit;r++){
+          const lat=gYs[r];
+          for(let c=0;c<w;c++){
+            const val=gTileValues[r][c]; if(val==null) continue; const dbz=Number(val); if(!(dbz>=40)) continue;
+            const lon=gXs[c]; const dist=haversine(gStLat,gStLon,lat,lon);
+            if(dist <= radiusM){ hit=true; maxDBZ = maxDBZ==null?dbz:Math.max(maxDBZ, dbz); break; }
+          }
+        }
+        if(hit){ el.textContent = `附近8km可能有降雨（≥40 dBZ）`; el.classList.remove('text-gray-700'); el.classList.add('text-red-700'); }
+        else { el.textContent = `附近8km未检测到≥40 dBZ 回波`; el.classList.remove('text-red-700'); el.classList.add('text-gray-700'); }
+      }catch(e){ /* ignore */ }
+    }
+
     async function main() {
       await loadStations();
       // 初始化时间范围为最近24小时
@@ -524,6 +558,7 @@
           最近距离：<span id="sectorDist"></span> km；预计到达时间：<span id="sectorETA"></span><br>
           位置：lat=<span id="sectorLat"></span>，lon=<span id="sectorLon"></span> 组合反射率：<span id="sectorDBZ"></span> dBZ
         </div>
+        <div id="nearbyStatus" class="mt-1 text-gray-700"></div>
       </div>
     </div>