How does Apple 7plus add weather and delete cities?

Enter "weather" in the phone interface.

2. Click on the three columns in the lower right corner after entering.

After entering at 3 o'clock, click the "plus sign" and search for the required city to add the city. If you want to delete, just draw the added city to the left, and the "Delete" button will appear. Click Delete so that you can delete the city.