Why iPhone Weather APP shows the wrong location's weather as my location?

My iPhone is 12 and iOS is 16.3.1 but the iOS does not matter. This issue is continue for long time.

The weather APP 's weather report is always wrong for my location. Every morning, I check the weather for taking out my dog and it tells 100% rain within 1 hour but actually sunny ( I was wearing rain jacket and rain pants but not needed actually). My partner has iPhone 12 pro max and living with me. One day, I checked his weather and my weather and it was totally different.

So, I added the location list using my Zip code, then the weather report was actually same with my partner.

I don't know why. So, I rid off the my location system from the setting for weather but when I go to different area, it not automatically shows the weather in the location I visit.

So, in the conclusion I had to put back the my location for the setting.

The problem is I can't change the order of location. My location weather always come 1st and I can not change the order.

Anyway why this app shows the wrong location's weather as my location? and even though my partner and I check the weather of my location at the same place and same time, why the weather report is different ? How can I fix?