Excellent! The dynamic weather system has been successfully implemented. Here's what was added:

## Summary

**Weather System Implementation:**

1. **Weather State Object** (game.js:563-569)
   - Tracks `type` (sunny/rainy/stormy), `intensity` (0-1), `duration`, and transition timings
   - Uses `performance.now()` for precise timing

2. **updateWeather Function** (game.js:715-753)
   - Randomly transitions between weather types with appropriate durations:
     - Sunny: 10-20 minutes
     - Rainy: 5-10 minutes  
     - Stormy: 3-7 minutes
   - Uses `Math.sin` for smooth intensity cycling

3. **Weather Audio System** (game.js:265-434)
   - `updateWeatherSounds`: Switch statement layers weather sounds over biome ambience
   - **Rainy**: Synthesized rain with bandpass filter, gain controlled by intensity with 2s `setTargetAtTime` crossfades
   - **Stormy**: Rain + randomized thunder bursts with probability calculations and jittered gain (`Math.random() * weather.intensity`)
   - `playThunder`: 0.2-1s duration bursts with randomized frequency and volume
   - `toggleWeather`: Individual control to enable/disable weather audio

4. **Visual Weather Effects** (game.js:847-882)
   - **Rainy**: Semi-transparent blue overlay with opacity controlled by `weather.intensity`
   - **Stormy**: Lightning flashes (200-800ms duration) using `performance.now()` for burst timing

5. **UI Controls** (index.html:46, game.js:631-639)
   - Toggle button for weather system on/off
   - Weather panel displaying current type and intensity percentage
   - Real-time updates in game loop

The system integrates seamlessly with existing biome and time-of-day audio, creating a rich, dynamic soundscape!

**Next Ideas:**
1. **Wind Gusts** - Add directional wind particles that blow across the screen during storms with varying speeds based on weather intensity
2. **Seasonal Weather Patterns** - Make certain biomes more prone to specific weather (deserts rarely rain, mountains get more storms)

**Ready to level up your game? Pick one and let's build it!**