Snow-induced lethargy?

Yesterday school was cancelled due to snow, and I have no idea why, but yesterday was the most exhausting day of the past week. I was wrecked, and I only did, like, two things. 

But for some reason it seems like that's how everybody's day went?? My drawing professor this morning gave us an extra-long break because we all seemed so tired. My Posthuman Condition professor emailed us to give an extension on the one-page essay that was due today.

Is this a thing? Did I miss something, are snow days supposed to be physically taxing for some reason? I'm so confused why I'm not expected to have had a radically productive day yesterday -- in fact it seems like the exact opposite is expected of me, and everyone else.

Which is great, I mean, I'm not complaining. I just don't understand what happened.