Chicago, IL – June 2024 saw unusually high temperatures across Illinois, with average temperatures exceeding norms by more than 3 degrees. According to the US National Weather Service Chicago, the monthly average temperature in Chicago (O’Hare) was 73.9°F, 3.3 degrees above normal, making it the 10th warmest June on record. Rockford also experienced significant warmth with an average temperature of 73.7°F, 3.6 degrees above normal, ranking as the 8th warmest June in its history.