Chicago, Illinois – January 2026 featured sharp temperature swings and a bitterly cold finish across northern Illinois.
According to the National Weather Service Chicago, the month opened unusually warm, with high temperatures reaching the upper 50s to lower 60s on January 8 and 9. Daily record highs were set in Rockford, while Chicago recorded one of its warmest January days on record. That warmth also contributed to heavy rainfall, including 1.92 inches on January 8 in Chicago, now the city’s wettest January day on record.
Conditions shifted noticeably by mid-month. Temperatures trended downward, and the first stretch of bitter cold arrived January 19, with wind chills between -20° and -25° affecting travel along Interstates 90, 94, and 39. Even colder air followed January 23–24, when wind chills dropped near -40° in some locations, and actual air temperatures bottomed out near -10°.
For the month, Chicago O’Hare averaged 21.9 degrees, about 3.3 degrees below normal, while Rockford averaged 19.1 degrees, 2.7 degrees below normal. Precipitation totals varied, with Chicago recording 2.53 inches, slightly above normal, while Rockford measured 0.82 inches, below average.
Snowfall distribution was uneven. Chicago officially received 11.3 inches, right at the monthly average, while Rockford picked up just 4.7 inches, roughly 6 inches below normal. Heavier lake-effect snow favored areas closer to Lake Michigan, leaving inland locations with lighter totals.
Commuters, students, and young workers traveling daily along I-90, I-94, and I-88 experienced both early-month warmth and late-month hazardous cold within the same month.
The National Weather Service emphasized that January 2026 was defined less by consistency and more by extremes, ending much colder than it began.
