So many from my tenure as STH...the playoff game vs Tennessee in 03, something like 5 degrees at kickoff. We had an ez up w sides and a propane htr going and it was fairly warm at our tailgate...but during the game, yikes, bought beers and by the time we got back to the seats they were Coors lt slushies....of course, snowbowl vs Oakland...for me a real bad one was 93 vs Indianapolis...was very cold and I went to the game woefully unprepared. Had plenty of layers but wore sneakers...from that day on for every cold game we brought a blanket FOR OUR FEET so our feet weren't on the freezing cold concrete for 3 hours straight. I lost feeling in parts of my feet and when I got home there was lots of purple...ouch, probably close to frostbite.
The most miserable game was a game vs the NYJ (I think), in the 09-12 range iirc. It snowed 4 or 5 inches overnight, then gradually warmed up a tad and turned to rain around 10ish. But the ground was still cold so everything in the parking lot (we were in P10 towards the back) was freezing and it became a literal skating rink.
It cold rained the entire game...sitting in that was not fun...