Dangerously cold weather descended on the Chicago area early Friday, sending temperatures plunging into the negative 20s.
The entire Chicago area was under a Wind Chill Advisory beginning at 6 p.m. CST Thursday and lasting through 12 p.m. Friday.
Residents were urged to take extra precautions if going outside, as the advisory warned of wind chills at 20 or even 30 degrees below zero.
The cold wind chills could cause frostbite on exposed skin in as little as 10 minutes, the National Weather Service said.
Friday is set to be the coldest day so far this winter. High temperatures were expected to only rise into the single digits for the afternoon, but wind chill readings will remain well below zero.
Light snow could leave behind a dusting to a half-inch of accumulation in far northern counties and up to an inch in areas south.
The weekend stays bitter with highs sitting between 6 and 12 degrees Saturday with below-zero wind chills once again.
Temps are set to rise into the teens by Sunday with more snow likely by Monday.