Remove the ads from the weather app. Not acceptable. I'm paying you for hardware and then you go and shove ads into the apps. Gross. You're all awful.
Erase data and uninstall updates... force stop and remove background activity for the battery and data usage while turning off its ability to run on data saver. Then deny all permissions and deny any appear on top, change system settings and such then disable it. Go to your apps setting menu, top right 3 dot more options, special access.. go to change system settings and enter it. Then top right menu again a show system apps, then turn off every single app that has that turned on. No app needs that ability when your not in the app using it so the parent app group leader, this case Samsung probably, can't go turn it back on and reset it. Then just use your browser and set the home page to weather, don't use current location, pick favorites and select a city close to yours so it's that info. Then depending on the browser you will either need to allow that browser to send notifications or allow it to show on the home/lock screen. Or use the widget selection for that browser and use the one with weather on it. Place where you want and... that'll don't it bud.