I took a few summer courses at the University of Minnesota once. They were in the process of digging underground tunnels between the basements of several buildings and insulating them with big slabs of styrofoam so students could go from building to building without actually having to go outside.

Allegedly, an out of state freshman or two wander off every year during a snowstorm. Usually the St Bernard's find them in time.

Average MSP temps (deg F)

Hi. Lo
24 8 January
29 13 February
41 24 March