Science & Nature
Chicago Area Cleaning Up After Powerful Storms Cause Flooding and Downed Trees
Fallen trees blocked streets and sidewalks throughout Chicago on Monday, including Lincoln Square seen here, following a pair of storms packing heavy rains and strong winds. (Patty Wetli / WTTW News)
After going three weeks without measurable precipitation, Chicago was hammered by a pair of storms on Monday that dumped nearly three inches of rain at Midway Airport, where wind gusts topped 70 miles per hour.
The city’s official weather station at O’Hare Airport recorded 1.76 inches of rain and a 65 miles per hour gust.
The 2.94 inches of rain at Midway marked the second time in July that nearly a month’s worth of rain fell in a single day. The average rainfall total for the entire month of July is 3.71, according to the National Weather Service.
The deluge overwhelmed sewer systems, flooding streets and homes.
Chicago’s Office of Emergency Management and Communications (OEMC) said it had received 569 reports to 311 of water on the street and 540 reports of water in basements.
As of early Tuesday morning, the Metropolitan Water Reclamation District’s Deep Tunnel reservoirs are holding a combined 6 billion gallons of stormwater and wastewater.
The McCook reservoir, serving central Chicago and 36 municipalities, was approximately 92% full and holding 3.2 billion gallons of water. McCook has hit capacity six times in 2026, most recently following heavy rains in early July. Previously, McCook had filled five times total between 2021 and 2025.
The Thornton reservoir, serving the South Side of Chicago and 13 south suburban municipalities, was 39% full and holding 3 billion gallons. Prior to Monday’s rains, Thornton and McCook were both still retaining some wastewater from early July.
Strong winds provided a one-two punch, downing trees and power lines across the region.
OEMC received nearly 2,000 tree emergency reports from Chicagoans and another 725 reports of tree debris as of Tuesday morning.
The National Weather Service’s Chicago office said it would be sending out survey teams to assess damage and confirm whether any tornadoes touched down in the region.
Approximately 215,000 ComEd customers remained without power Tuesday morning, down from a peak in excess of 500,000, company officials said.
The utility said it expects to resolve 80% of those outages by noon on Wednesday and nearly all of them by Friday evening.
Contact Patty Wetli: [email protected]
