1. Minus 28, with a wind chill reaching minus 53.

Those were the numbers in one city, Minneapolis, as the polar vortex blasted through the Midwest, and overnight temperatures are expected to go still lower. Much of the region has come to a standstill. At least eight deaths have been connected to the cold weather system.

This 3-D model shows how the vortex works. Above, looking out over frigid Chicago.

There were moments of strange beauty, like the frigid mist rising from Lake Michigan, and also oddities: “frost quakes” may have hit Pennsylvania, Ohio and Illinois. Here’s our roundup of the day’s weather reporting.