@wadoadi @windy1994 @Korina I did the same reset the Apple Watch app from the iPhone application. For others, if somebody would have the same issue, here you have a little help.
If the new features did not appear after you updated the iPhone Windy application you can follow the following steps to make the new functions available on your Apple Watch:
open the Watch app on your iPhone
scroll down and open Windy app (you will find it under "Installed on Apple Watch")
Toggle OFF the "Show App on Apple Watch" option and then turn it ON again
wait some seconds until it will appear again on your Apple Watch
open the Windy app on your Apple Watch and magic happens, from now it will shows all of the new features:)
I hope it helps!:)