Sounds like something out of science fiction, right? These are relatively rare, but sometimes, the temperature can jump rapidly in the early morning hours, like it did this morning in Perham, MN. So, how does it happen? What do you need to see the thermometer jump almost 20° without much warning? There are two big ingredients you'll need: a dying storm and some warm air just off the surface.
As that storm falls apart, the rain-cooled air will shove the warmer, drier air down to the surface. The temperature shot from about 80 all the way up to 97 in a matter of 30 minutes between 7:00 and 8:00 AM.
Usually, these happen in the morning hours, when an inversion will displace the warmer air aloft as we cool off overnight.