Why does Apple always verify the city by adding weather?

The network is unstable, and the operation method is as follows:

1. First open the "Weather" APP of Apple's mobile phone, as shown in the figure.

2. Open the weather APP and click the option at the bottom right, as shown in the figure.

3. Then click+in the dialog box to enter the next interface, as shown.

4. Then enter the name of the city you want to view in the search bar, and search for a choice, as shown.

5. Complete the above steps to complete the increase of weather forecast cities, as shown in the figure.