I don't want to "akshually" this, but on a stock[1] up-to-date Windows 11 x64 25H2 (aka: my desktop) Weather takes up around ~670MB of RAM at launch, not 1GB. While writing this comment it dropped to 450MB. All in all much lower than 1GB.
1: i.e.: not "debloated" or running a bunch of random customizer scripts.