Chicago will be in the grip of dangerous heat Wednesday and Thursday, with oppressive humidity likely to send heat indices soaring as high as 115 degrees, according to the National Weather Service.

By 2:25 p.m. Wednesday, the temperature at Chicago O’Hare International Airport had reached a record-breaking 98 degrees. The previous highest recorded temperature for Aug. 23 was 97 degrees; that record was set in 1947. The heat index at O’Hare reached 112 degrees Wednesday, the National Weather Service said, while the heat index at Chicago Midway International Airport hit 115 degrees.

[5:37 AM 8/23] A period of dangerous heat and humidity arrives today. Peak heat indices will be in the 105 to 115 degree range both today and tomorrow. Some potential for a cold front to arrive Thu. PM across NE IL which could reduce the duration of heat a bit lakeside. pic.twitter.com/PeEwW0Mr7F

— NWS Chicago (@NWSChicago) August 23, 2023

Air conditioning is the best way to beat the heat, but for people who work outdoors or lack a/c indoors, here are ways to keep cool:

— Take advantage of cooling centers, including libraries.

— Head to a Park District splash pad, which are staying open this year through the end of September.

— Stay hydrated; wear loose, light, cotton clothing.

— Turn off lights and electronics when not needed.

— Don't leave people or pets in a closed car, even for a few minutes.

Be aware of the signs of heat exhaustion and heat stroke:

Here are some ways to identify heat exhaustion and heat stroke in yourself or loved ones. Visit https://t.co/0pNEAyurgr for more information. pic.twitter.com/OcWHJoeOND

— NWS Chicago (@NWSChicago) August 21, 2023

If you have plans to attend an outdoor event Wednesday or Thursday, call ahead to make sure it hasn't been canceled. Chicago Public Schools has postponed all outdoor athletic games scheduled for Wednesday and Thursday, and all practices have been canceled or moved indoors, CPS said.

The city of Chicago is expanding hours at six cooling centers on Wednesday and Thursday from 8:30 a.m.-7 p.m.:

City of Chicago cooling centers:

• Englewood Center – 1140 W. 79th St.    
• Garfield Center – 10 S. Kedzie Ave. (24 hours)   
• King Center – 4314 S. Cottage Grove Ave.
• North Area Center – 845 W. Wilson Ave.    
• South Chicago Center – 8650 S. Commercial Ave.    
• Trina Davila Center – 4312 W. North Ave.

Additional locations activated as cooling centers from 8:30 a.m.-4:30 p.m. Wednesday and Thursday include:

Regional service centers:

• Southeast – 1767 E. 79th St.
• Southwest – 6117 S. Kedzie Ave.
• Central West – 2102 W. Ogden Ave.
• Northeast – 2019 W. Lawrence Ave.
• Northwest – 3160 N. Milwaukee Ave.
• Renaissance Court – 78 E. Washington St. (10 a.m.-5 p.m.)

Satellite senior centers:

• Pilsen – 2121 South Morgan St.
• West Town – 1615 West Chicago Ave.   
• North Center – 4040 North Oakley Ave.
• Norwood Park – 5801 North Natoma Ave.
• Portage Park – 4100 North Long Ave.
• Abbott Park – 49 East 95th St.
• Chatham Park – 8300 South Cottage Grove Ave.
• Roseland – 10426 South Michigan Ave.
• Garfield Ridge – 5674-B South Archer Ave.
• Kelvyn Park – 2715 North Cicero Ave.
• Auburn Gresham – 1040 West 79th St.
• Englewood – 653-657 West 63rd St.
• Austin – 5071 West Congress Parkway
• Edgewater – 5917 North Broadway
• South Chicago – 9233 South Burley Ave.

A cold front is expected to push into the area on Thursday, bringing much needed relief, though meteorologists are still uncertain about the timing. 

Some uncertainty remains regarding the timing of a cold front on Thursday which will quickly cool conditions behind it. While oppressive heat remains likely across the whole area, conditions not far from the lake will remain notably cooler if the front arrives earlier in the day. pic.twitter.com/TfUYKVwNcV

— NWS Chicago (@NWSChicago) August 22, 2023

Contact Patty Wetli: @pattywetli | (773) 509-5623 |  [email protected]