You think cold weather changes class schedules?
I am wondering, yes.
For fair weather terrorists, it sure does. When my kid was in Iraq, they could 'predict' attacks based on the weather. If it was hot, or rainy, or sandstorms, or cold, or prayer time (I know, not weather related, but you get the drift), the attacks plummeted. So, if it was snowing in September in Montana, I'm sure they the terrorists had weather related 'issues'. :)