This past December in Chicago tied for the area’s fourth warmest December on record, according to the National Weather Service. The average temperature of 39 degrees landed 8.5 degrees above normal.

The minimum Chicago area temperature was 17 degrees on Dec. 19. The maximum temperature reached 59 degrees on Dec. 25. Christmas Day’s low of 50 degrees set the daily record for highest minimum temperature. 

These high temperatures led to slightly higher rainfall and lower snowfall than average, NWS reported. 

2023 saw the return of El Niño, an episodic warming of Pacific waters that impacts global weather patterns. According to NWS senior meteorologist ​​Brett Borchardt, El Niño typically favors a warmer winter. December 2015, whose average temperature was also 39 degrees,  experienced strong El Niño effects as well. 

1877 saw the warmest December on record with an average temperature of 43 degrees.

Chicagoans hoping for a mild rest of the winter shouldn’t stow their coats quite yet. High December temperatures don’t necessarily mean the season will stay that way, Borchardt said. NWS predicts a “strong” storm will hit the area by early next week. 

“We’ve actually seen in the past few winters that December and even November have been warmer than past Decembers and Novembers, but with that said, Januaries, Februaries and even Marches have still been winter-like, so there’s unfortunately not much predictive skill,” Borchardt said.