Hello Music1357,
Thanks for that info and for choosing the Apple Support Communities. If we understand correctly, you are unable to find the Weather app on your Apple Watch, but it is still on your iPhone and shows that it should be on your Apple Watch in the Watch app. If you haven't already, please restart your Apple Watch and your iPhone and then test your situation again and see if the Weather app shows on your Apple Watch as expected.
How to restart your Apple Watch
Restart your iPhone
Open apps on Apple Watch
If you are still having this issue, try temporarily unpairing your Apple Watch from your iPhone and removing the Weather app from your iPhone. Then pair your Apple Watch with your iPhone and reinstall the Weather app and see if you can get the Weather app on your Apple Watch again.
Unpair and erase your Apple Watch
Delete built-in Apple apps on your iOS 12, iOS 13, or iPadOS device or Apple Watch
Set up your Apple Watch
Cheers!