To change the weather location on an iPhone, iPad, or Apple Watch, follow these steps:

On iPhone:

  1. Open the Watch app on your iPhone if you have an Apple Watch.
  2. Navigate to "My Watch" (tab).
  3. Select "Weather" and then choose "Default City."
  4. Set your default city to "Current Location" or choose another city from the list. Make sure that "Mirror my iPhone" is selected if you want the location to match your iPhone's weather app.

On Apple Watch:

  1. Open the Settings app on your Apple Watch.
  2. Tap "Weather," then "Default City."
  3. Choose your desired city, or select "Current Location" to set your location dynamically.

Additionally, ensure that Location Services is enabled for the Weather app on both devices:

On iPhone:

  1. Go to "Settings" on your iPhone.
  2. Tap "Privacy & Security," then "Location Services."
  3. Ensure that "Weather" is enabled, and you can choose the desired Location Precision.

Remember that your list of locations in the Weather app will be synced across these devices when you're signed in with the same Apple ID.