Science & Nature
July in Chicago Was Hotter and Wetter Than Normal, Weather Service Says
(Steve Godomski / iStock)
A pair of storms on the front and back ends of July made for a wetter month than normal, according to a National Weather Service summary.
Total precipitation for the month, measured at O’Hare Airport, was 5.36 inches. That’s 1.65 inches more than typically falls in July, but almost all of the rain was recorded on just three days: July 2-3 and July 27. In between, there was a three-week stretch with no measurable rain.
The 1.71 inches of rain notched on July 3 set a new daily record for Chicago.
The intense storms at the beginning of the month led to flash flooding and the unprecedented situation of the Metropolitan Water Reclamation District’s (MWRD) two largest reservoirs and tunnels reaching 100% of their capacity.
Chicago’s sewer system was overwhelmed by the heavy downpours, which dumped large amounts of rain in a short amount of time.
The MWRD reported numerous combined sewer overflows at locations up and down the Chicago River and Des Plaines River, sending untreated wastewater into the rivers. There have been more days with overflows so far in 2026 than in the previous two years combined.
Storms did provide relief from extreme heat at the beginning of the month, which boosted July’s average temperature to 76.8 degrees, or 1.4 degrees above normal. On July 1, the overnight low temperature of 80 degrees set a daily record.
While Chicago’s climate data goes back to 1871 for precipitation and 1872 for temperatures, there’s no historical baseline for wildfire smoke, which blanketed the region in mid-July and resulted in dangerous air quality.
Contact Patty Wetli: [email protected]
