Hi
The following steps may help:
If you have not yet done so, update your iPhone and Apple Watch to the latest software, starting with your iPhone:
- Update the iOS software on your iPhone, iPad, or iPod touch - Apple Support
- Update the software on your Apple Watch - Apple Support
On your iPhone, in the Watch app, go to: My Watch (tab) > Weather > Default City > choose Current Location (or a specific location from those that have been added to the Weather app on your iPhone, if preferred).
On your iPhone, go to: Settings > Privacy > Location Services:
- Check that Location Services is enabled.
- If the setting is already turned on, try turning it off, pausing for a few moments and then re-enabling it.
- Check that Apple Watch Faces is set to While Using.
- Toggling the setting to Never and back again may help.
- Check that Weather is set to Always
- Toggling the setting may help.
Check that Bluetooth and Wi-Fi are both enabled on your iPhone:
- iPhone: Settings > Bluetooth - on.
- iPhone: Settings > Wi-Fi - on.
- For the best performance from your watch, keep both Bluetooth and Wi-Fi permanently enabled on your iPhone.
On your iPhone, go to: Settings > General > Background App Refresh:
- Check that Background App Refresh is enabled.
- It may also help to enable the setting for Weather.
On your iPhone, in the Watch app, go to: My Watch > Complications:
- If you are currently using a third-party weather app (such as Yahoo Weather) for your watch face complications, try removing it (via Edit, upper-right) and using Apple's built-in Weather app instead.
The following further steps may also help:
Restart both your iPhone and your watch, turning both devices off together, then restart your iPhone first;
Unpair and re-pair your watch:
- The Watch app on your iPhone takes a backup of your watch automatically when unpairing via the app. Choose to Restore from Backup during set up. Most data and settings will be restored, with some exceptions (eg Apple Pay cards, passcode).
- Unpair your Apple Watch and iPhone - Apple Support
- Set up your Apple Watch - Apple Support