Moody Weather

What is it about the weather that can affect one's mood so much? Without even seeing the forecast, you could probably tell it's been overcast and raining the past few days just by talking to me. I have been unmotivated, grumpy and generally in a blah mood because of the weather. I've heard that you get wiser with age and, while I don't generally agree with that (I've found that the older I get the more I realize I don't know), one thing I have learned is how the weather can affect my mood. While sunshine can make me happy and motivated, humidity makes me downright irritable. Snow has a calming affect on me (unless I'm driving on Hwy 395 during rush hour~ and I use the term "rush hour" loosely) but rain makes me unmotivated and tired. Some wind and cold temperatures on a Bluebird Day make me downright giddy! Yes, there have been many days where I've been happy when it's raining and unmotivated when it's sunny but I still find it weird how something as simple as weather can make a break your mood for the day. Hopefully the sun will come out soon and I'll break out of this funk because my "To Do" list doesn't seem to be getting done on it's own!