When it rains here, it is usually not very warm, but it rains cats and dogs and lightnings and thunders ! Yikes you get the idea. If it looks like it is going to rain, I carry one of those clear plastic looking bike rain jackets. They do not breathe well, but I'm just trying to stay warm when it is raining here (even in the summer) so it usually works out okay.

If it is not cold, I might wear a wind breaker or nothing but my regular kit.