Many years ago, I stayed with a Bernese family (Therese, where are you now?), whose house had a splendid view of Bern's very own local mountain, the Gurten. After all these years, my brain has managed to retain the rhyme they taught me:
Hat der Gurten einen Hut
Ist das Wetter schön und gut.
Hat der Gurten einen Kragen
Darf man nicht vom Hause wagen.
It's probably more reliable than hanging out a piece of seaweed, something which I imagine is a rare commodity anyway in Switzerland.