How to check the weather forecast of 15 days on Apple's mobile phone?

1. Open the weather app that comes with Apple's mobile phone, as shown below:

2. Open the menu in the lower right corner and enter the Add City interface, as shown in the figure below:

3. Click the plus sign to add a city to know the weather, as shown in the figure below:

4. Enter the city name in the search box, and then select the city you want in the city candidate words that appear, as shown in the following figure:

5. You can see that the newly selected city already exists in the city interface, as shown in the following figure:

6. Click on the city to see the specific weather forecast of the city 15, as shown in the figure below: