February is the month of carnivals in Switzerland. They do not take place everywhere. For example Zürich doesn't have one. The most famous ones are in Lucerne and Basel. The carnivals do not happen at the same time everywhere, it's pretty much spread out over several weeks.
Last year I went to see the carnival in Baar, this year in Baden. Usually the carnival lasts at least the whole weekend and there are two parades - one parade for kids and the other one where the local carnival clubs participate. They prepare their costumes the whole year.
There are always lots of brass bands playing well-known hits. The goal is not to be perfect. In fact, it is supposed to sound a bit out of sync and out of tune.
And the biggest fun for people is to throw confetti on each other (as you can see the guy doing on the photo above). When you finally get home you will find confetti from the places you least expected :)
If you happen to visit Switzerland in February, check out if there are any carnivals taking place during your visit. It's definitely worth seeing.