Why can't iphone see the weather in Phuket?

Not all cities have weather forecasts.

But you can search the city and check the weather. The weather in Phuket can't be searched on the homepage.

Enter "Thailand" in the search bar, and only two major cities will be displayed below.

What is more certain is that all the big cities are displayed on the front page.

Enter Phuket in the pop-up "Search City, Zip Code or Airport Location", then Phuket will come out below, and you can see it by clicking again.