It's been an unseasonably warm start to the year in Chicago. With temperatures averaging in the mid to high 30s, the city is seeing its fourth warmest January on record.

Climatologist Trent Ford said the only years that were warmer were 1880, 1939 and 2006.

“Right around Christmas Eve, Christmas Day, we had a very cold pattern,” Ford said. “Since then, we’ve had some variability, but the larger scale atmospheric pattern that has actually kept a lot of California very wet for that time period has kept our winds coming out of the south and southwest unreasonably warm, somewhat humid air … . It’s just kept temperatures elevated anywhere between eight and 12 degrees above normal for really the last three weeks now. … It’s the persistence that’s pretty unusual.”

But don't get too excited, he said. The warmth can't last forever.

There are growing indications that Chicago will be returning to much more typical winter weather next week, if not below normal.

For those enjoying the mild January, all good things must come to an end. There are growing indications that a more typical winter weather pattern return the last week of Jan. Here's the latest 8-14 day outlook from @NWSCPC showing increased chances of colder than avg temps 3/3 pic.twitter.com/NcCeCbL2Cs

— NWS Chicago (@NWSChicago) January 17, 2023

“The rest of this week, the early part of next week, is still looking fairly mild, low to mid 30s, if not upper 30s,” Ford said. “But then we begin to shift to a chance of below-normal temperatures. To give you an idea, normal for the last week of January are highs right around 30, 31 degrees, close to that freezing mark. Below-normal temperatures means we’ll probably see highs in the mid to upper 20s. … It’s definitely moving out of the way.”