diff --git a/atmosphere/src/App.jsx b/atmosphere/src/App.jsx
index 3b6c48996..ed8c8534a 100644
--- a/atmosphere/src/App.jsx
+++ b/atmosphere/src/App.jsx
@@ -1,9 +1,9 @@
-import React, { useEffect, useRef, Suspense } from 'react';
+import React, { useEffect, useRef, Suspense, useState } from 'react';
 import { Canvas, useFrame, useLoader, useThree } from '@react-three/fiber';
 import { GLTFLoader } from 'three/examples/jsm/loaders/GLTFLoader';
 import { VRMLoaderPlugin, VRMUtils } from '@pixiv/three-vrm';
 import { createVRMAnimationClip, VRMAnimationLoaderPlugin } from '@pixiv/three-vrm-animation';
-import { AnimationMixer, Vector3 } from 'three';
+import { AnimationMixer, Vector3, MathUtils } from 'three';
 import { OrbitControls, PerspectiveCamera } from '@react-three/drei';
 import { EffectComposer, ToneMapping } from '@react-three/postprocessing';
 import { ToneMappingMode } from 'postprocessing';
@@ -18,81 +18,144 @@ const VRM_URL = '/ai.vrm';
 const VRMA_URL = '/fly.vrma';
 const EARTH_RADIUS = 6378137;
 
-// ★追加: 時刻を「2024年6月21日 12:00 (正午)」に固定するためのDateオブジェクト
-// 季節によって太陽高度が変わるため、夏至の昼を選んでおくと最も明るくなります。
-const FIXED_DATE = new Date('2024-06-21T12:00:00');
+// 天気変更の間隔 (ms) - 5分
+const WEATHER_INTERVAL = 5 * 60 * 1000;
+
+// 時間の進行速度 (倍率)
+const TIME_SCALE = 100; 
+
+// 初期時刻: 正午 (12:00)
+const INITIAL_DATE = new Date('2024-06-21T12:00:00');
+
+// --- Weather Presets (天候設定) ---
+const WEATHER_PRESETS = [
+  {
+    name: 'Clear (快晴)',
+    coverage: 0.1, 
+    layers: [
+      { channel: 'r', altitude: 1500, height: 500, densityScale: 0.0 },
+      { channel: 'g', altitude: 2500, height: 800, densityScale: 0.0 },
+      { channel: 'b', altitude: 7500, height: 500, densityScale: 0.1 }, 
+    ]
+  },
+  {
+    name: 'Sunny (晴れ)',
+    coverage: 0.4, 
+    layers: [
+      { channel: 'r', altitude: 1500, height: 500, densityScale: 0.4 }, 
+      { channel: 'g', altitude: 2500, height: 800, densityScale: 0.0 },
+      { channel: 'b', altitude: 7500, height: 500, densityScale: 0.2 },
+    ]
+  },
+  {
+    name: 'Cloudy (曇り)',
+    coverage: 0.75, 
+    layers: [
+      { channel: 'r', altitude: 1500, height: 500, densityScale: 0.6 },
+      { channel: 'g', altitude: 2000, height: 1000, densityScale: 0.5 }, 
+      { channel: 'b', altitude: 7500, height: 500, densityScale: 0.0 },
+    ]
+  }
+];
 
 // ---------------------------------------------------------
-// Scene 1: Atmosphere (奥・リアルスケール・HDR設定)
+// Scene Components (Inside Canvas)
 // ---------------------------------------------------------
 
-// 明るさ調整用のコンポーネント
-function ExposureController() {
+// Canvasの内側で動作するメインシーンコンポーネント
+function AtmosphereScene() {
   const { gl } = useThree();
+  const sunRef = useRef(); 
+  const atmosphereRef = useRef(); 
+  const dateRef = useRef(new Date(INITIAL_DATE));
+  const [weather, setWeather] = useState(WEATHER_PRESETS[1]);
+
+  // 1. 露出設定 (Canvas内なのでuseThreeが使える)
   useEffect(() => {
-    // Takramのライブラリは物理単位の光量を扱うため、
-    // 露出を劇的に上げる必要があります。
     gl.toneMapping = THREE.NoToneMapping;
     gl.toneMappingExposure = 10.0; 
   }, [gl]);
-  return null;
-}
 
-function AtmosphereLayer() {
-  const cameraRef = useRef();
+  // 2. 天候の定期変更
+  useEffect(() => {
+    const interval = setInterval(() => {
+      setWeather(prev => {
+        const others = WEATHER_PRESETS.filter(w => w.name !== prev.name);
+        const next = others[Math.floor(Math.random() * others.length)];
+        console.log(`[Weather] Changing to: ${next.name}`);
+        return next;
+      });
+    }, WEATHER_INTERVAL);
+    return () => clearInterval(interval);
+  }, []);
+
+  // 3. 時間進行と太陽移動 (Canvas内なのでuseFrameが使える)
+  useFrame((state, delta) => {
+    // 時間を進める
+    const currentDate = dateRef.current;
+    const elapsedMs = delta * TIME_SCALE * 1000;
+    currentDate.setTime(currentDate.getTime() + elapsedMs);
+
+    // Atmosphere更新
+    if (atmosphereRef.current) {
+      atmosphereRef.current.updateByDate(currentDate);
+    }
+
+    // 太陽移動
+    if (sunRef.current) {
+      const hours = currentDate.getHours() + currentDate.getMinutes() / 60 + currentDate.getSeconds() / 3600;
+      const sunAngle = MathUtils.mapLinear(hours, 6, 18, 0, Math.PI);
+      const sunX = -Math.cos(sunAngle);
+      const sunY = Math.sin(sunAngle);
+
+      if (hours < 6 || hours > 18) {
+          sunRef.current.position.set(0, -1, 0);
+          sunRef.current.intensity = 0.0;
+      } else {
+          sunRef.current.position.set(sunX, sunY, 0.2);
+          sunRef.current.intensity = MathUtils.lerp(0.5, 3.0, sunY);
+      }
+    }
+  });
 
   return (
-    <Canvas>
-      <ExposureController />
-      
+    <>
       <PerspectiveCamera 
         makeDefault 
-        ref={cameraRef}
         position={[0, EARTH_RADIUS + 2000, 0]} 
         near={1} 
         far={10000000}
         fov={45} 
       />
 
-      {/* 太陽: 真上(正午) + 強度アップ */}
       <directionalLight 
+        ref={sunRef}
         position={[0, 1, 0]} 
         intensity={3.0} 
+        castShadow
       />
 
-      {/* ★修正: date={FIXED_DATE} を渡して時間を固定 */}
-      <Atmosphere date={FIXED_DATE}>
+      <Atmosphere ref={atmosphereRef}>
         <EffectComposer multisampling={0} disableNormalPass={false}>
-          <Clouds disableDefaultLayers>
-            <CloudLayer 
-              channel='r' 
-              altitude={1500} 
-              height={500} 
-              densityScale={0.5}
-            />
-            <CloudLayer 
-              channel='g' 
-              altitude={2500} 
-              height={800} 
-            />
-            <CloudLayer
-              channel='b'
-              altitude={7500}
-              height={500}
-              densityScale={0.003}
-              shapeAmount={0.4}
-            />
+          <Clouds disableDefaultLayers coverage={weather.coverage}>
+            {weather.layers.map((layer, index) => (
+              <CloudLayer 
+                key={index}
+                channel={layer.channel}
+                altitude={layer.altitude}
+                height={layer.height}
+                densityScale={layer.densityScale}
+                shapeAmount={0.5}
+              />
+            ))}
           </Clouds>
-          
           <AerialPerspective sky sunLight skyLight />
-          
-          {/* 重要: AGXトーンマッピングで、高い露出でも色を綺麗にまとめる */}
           <ToneMapping mode={ToneMappingMode.AGX} />
         </EffectComposer>
       </Atmosphere>
       
       <FlyOverCamera />
-    </Canvas>
+    </>
   );
 }
 
@@ -117,7 +180,7 @@ function FlyOverCamera() {
 }
 
 // ---------------------------------------------------------
-// Scene 2: Avatar (手前・ローカルスケール)
+// Scene 2: Avatar
 // ---------------------------------------------------------
 function VrmCharacter() {
   const mixerRef = useRef(null);
@@ -158,7 +221,6 @@ function AvatarLayer() {
     <Canvas gl={{ alpha: true, antialias: true }}>
       <PerspectiveCamera makeDefault position={[0, 1.5, 3]} fov={30} />
       
-      {/* キャラのライティングは背景とは独立して、キャラが映える設定にする */}
       <directionalLight position={[-1, 1, 1]} intensity={1.5} />
       <ambientLight intensity={1.0} />
       <spotLight position={[0, 2, -2]} intensity={3} color="#ffdcb4" />
@@ -175,6 +237,15 @@ function AvatarLayer() {
 // ---------------------------------------------------------
 // Main App
 // ---------------------------------------------------------
+function AtmosphereLayer() {
+  // Canvasが親となり、その中にロジックコンポーネント(AtmosphereScene)を入れる
+  return (
+    <Canvas>
+      <AtmosphereScene />
+    </Canvas>
+  );
+}
+
 export default function App() {
   const layerStyle = {
     position: 'absolute',
@@ -187,7 +258,7 @@ export default function App() {
   return (
     <div style={{ position: 'relative', width: '100vw', height: '100vh', background: '#000' }}>
       
-      {/* Layer 0: Atmosphere (明るさ補正済み) */}
+      {/* Layer 0: Atmosphere */}
       <div style={{ ...layerStyle, zIndex: 0 }}>
         <AtmosphereLayer />
       </div>