How to add city weather to Apple Watch?

Hello! If you mean adding and deleting cities in the Apple Watch weather software, you only need to operate in the weather software that comes with the iPhone:

1. Keep the Apple Watch connected to the iPhone, and open the weather software that comes with the iPhone.

2. After entering the weather, click the icon on the lower right to enter the city list interface.

In the lower right corner of the city list, there is a+sign. Click this plus sign, enter the city name in the search field, and then click the searched city link to add a city.

4. Click on the added city icon and paddle to the left. A delete button will appear to the right of the icon. Click it to delete the city.