diff --git a/Ananta.Server/Ananta.App/DebugApiServer.cs b/Ananta.Server/Ananta.App/DebugApiServer.cs
index c28bc86..42feb05 100644
--- a/Ananta.Server/Ananta.App/DebugApiServer.cs
+++ b/Ananta.Server/Ananta.App/DebugApiServer.cs
@@ -118,6 +118,8 @@ internal sealed class DebugApiServer(PrivateServerConfig config, GameSessionHub
                 await WriteJsonAsync(ctx, TimeStatus(), token);
             else if (method == "POST" && path == "/api/time/set")
                 await WriteJsonAsync(ctx, await TimeSetAsync(await ReadBodyAsync(ctx.Request, token), token), token);
+            else if (method == "POST" && path == "/api/weather/set")
+                await WriteJsonAsync(ctx, await WeatherSetAsync(await ReadBodyAsync(ctx.Request, token), token), token);
             else if (method == "POST" && path == "/api/world/switch-scene")
                 await WriteJsonAsync(ctx, await SwitchSceneAsync(await ReadBodyAsync(ctx.Request, token), token), token);
             else if (method == "POST" && path == "/api/unstuck/blackscreen")
@@ -865,6 +867,41 @@ internal sealed class DebugApiServer(PrivateServerConfig config, GameSessionHub
         return new { ok = true, hour, minute, fix };
     }
 
+    private async Task<object> WeatherSetAsync(string json, CancellationToken token)
+    {
+        var session = hub.Current;
+        if (session is null)
+            return new { ok = false, error = "no live game session (is the client in the world?)" };
+
+        uint weatherId = 1, transition = 5;
+        try
+        {
+            using var doc = JsonDocument.Parse(string.IsNullOrWhiteSpace(json) ? "{}" : json);
+            var root = doc.RootElement;
+            if (root.TryGetProperty("weatherId", out var pw))
+                weatherId = pw.GetUInt32();
+            if (root.TryGetProperty("transition", out var pt))
+                transition = pt.GetUInt32();
+        }
+        catch (Exception ex)
+        {
+            return new { ok = false, error = $"bad request: {ex.Message}" };
+        }
+
+        var state = GameRouter.GetStateIfExists(session);
+        if (state is null)
+            return new { ok = false, error = "no live game session (is the client in the world?)" };
+        lock (state.SyncRoot)
+        {
+            state.WeatherId = weatherId;
+            state.WeatherTransitionSeconds = transition;
+            state.HasExplicitWeather = true;
+        }
+        await GameRouter.PushSessionWeatherAsync(session);
+        session.Log.Info($"[DEBUG-API] weather set id={weatherId} transition={transition}s");
+        return new { ok = true, weatherId, transition };
+    }
+
     private async Task<object> UnstuckBlackScreenAsync(CancellationToken token)
     {
         var session = hub.Current;
diff --git a/Ananta.Server/Ananta.App/DebugPanel/index.html b/Ananta.Server/Ananta.App/DebugPanel/index.html
index a593a40..171c601 100644
--- a/Ananta.Server/Ananta.App/DebugPanel/index.html
+++ b/Ananta.Server/Ananta.App/DebugPanel/index.html
@@ -39,6 +39,25 @@
   <div class="muted">00:00 — night &nbsp;·&nbsp; 06:00 — morning &nbsp;·&nbsp; 12:00 — noon &nbsp;·&nbsp; 18:00 — evening &nbsp;·&nbsp; 23:59 — night</div>
 </div>
 
+<div class="card">
+  <h2>Weather / Atmosphere (สภาพอากาศ)</h2>
+  <div>
+    <button style="background:#fbc02d;color:#222;font-weight:bold" onclick="setWeather(1)">☀️ Sunny (แดดออก)</button>
+    <button style="background:#78909c" onclick="setWeather(2)">⛅ Cloudy (มีเมฆมาก)</button>
+    <button style="background:#1976d2" onclick="setWeather(3)">🌧️ Rain (ฝนตก)</button>
+    <button style="background:#512da8" onclick="setWeather(4)">⛈️ Storm (พายุฝนฟ้าคะนอง)</button>
+    <button style="background:#757575" onclick="setWeather(5)">🌫️ Fog (หมอกลงจัด)</button>
+    <button style="background:#455a64" onclick="setWeather(6)">🌥️ Overcast (มืดครึ้ม)</button>
+    <button style="background:#303f9f" onclick="setWeather(7)">🌙 Night / Snow (หิมะ/กลางคืน)</button>
+  </div>
+  <div style="margin-top:8px">
+    Custom Weather ID: <input id="customWeatherId" type="number" style="width:90px" value="1">
+    Transition (sec): <input id="weatherTransition" type="number" style="width:70px" value="5">
+    <button class="ghost" onclick="setCustomWeather()">Apply Custom Weather</button>
+  </div>
+  <div class="muted" style="margin-top:6px">ซิงค์สภาพอากาศของโลกและบรรยากาศ client ทันที</div>
+</div>
+
 <div class="card">
   <h2>Garage (server vehicles)</h2>
   <div style="margin-bottom:10px;padding:8px;background:#252932;border-radius:6px">
@@ -425,6 +444,18 @@ async function toggleClothes() {
   log('toggle clothes: ' + JSON.stringify(r));
 }
 
+async function setWeather(weatherId) {
+  const transition = parseInt(document.getElementById('weatherTransition')?.value || '5', 10);
+  const body = { weatherId: parseInt(weatherId, 10), transition };
+  const r = await api('/api/weather/set', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(body) });
+  log('set weather: ' + JSON.stringify(r));
+}
+
+async function setCustomWeather() {
+  const id = parseInt(document.getElementById('customWeatherId').value || '1', 10);
+  await setWeather(id);
+}
+
 function onEnemyPresetChange() {
   const sel = document.getElementById('enemypreset').value;
   if (sel !== 'custom') {