In macOS 15.2 you now can add the weather status to the menu bar of your Mac without installing a dedicated app.

A user guide describes how to enable weather in the menu bar: In System Settings click Control Center in the sidebar, scroll down and in the Menu Bar Only section next to Weather choose Show in Menu Bar.

If you want you can move the weather status in the menu bar by pressing the command key, grabbing it with the cursor and dragging.