Oh, sure! Weather and behavior certainly can be related. Besides the SAD phenomenon discussed above, there can be other issues. Some people get headaches (even full-blown migraines) when the barometer pressure rises or falls. The first day of a major weather change, I'll have a nasty little headache, and that certainly affects my moods. Also, certain molds can pop up pretty quickly when it's suddenly moist, and that can cause allergies, which can then cause some behavior issues. Changes in routine (which can occur when there's rain, snow, excessive heat etc) affect behavior, so you can say that's weather-related. Being stuck inside with less exercise and more social stress can do it, too. You have a lot of choices for correlating behavior issues with weather! Good luck sorting it all out!