Tags representing certain weather conditions can be very useful for organizing indoor or outdoor activities on a "Someday Maybe" list. I started to collect things I'd like to do in the city or outdoors (like going on a hike, a visit to a museum, going swimming etc...) and started to add tags representing weather conditons like "rainy", "sunny", "hot", "dry" to them. So, on the next rainy weekend I can easily filter for things to do using smart lists or the tag cloud.