Hello Sky765,
If the Weather app isn't working on your new Apple Watch, then we'd follow these related steps for a solution: If the Apple Watch Weather complication isn't working
If the Apple Watch Weather complication isn't working
Learn what to do if weather data on your Apple Watch isn't loading or shows "--".
Reset your iPhone settings
Follow these steps:
1. On your iPhone, open the Settings app, then tap Privacy & Security > Location Services.
2. Scroll down and tap Weather.
3. Under Allow Location Access, tap Never, then tap your original setting.
4. Check whether the issue is resolved.
If weather data still doesn't load, try these steps:
1. On your iPhone, open the Settings app, then tap General > Transfer or Reset iPhone.
2. Tap Reset > Reset Location & Privacy.
3. If prompted, enter your passcode and reset.
4. Check whether the issue is resolved.
If these don't resolve the issue, then it would be best to contact Apple Support directly: Get Support They will need to take it from here.
Cheers!