National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Dangerous Heat and Heavy Rainfall into the Weekend

Hot temperatures and high humidity are forecast to continue across the mid-Mississippi Valley into this weekend. Heat Advisories remain in effect. Heavy to excessive rainfall occurring at times through the weekend could bring areas of flooding to parts of the northern Rockies, upper Midwest, central Great Lakes, and southern New England. Read More >

Hazardous Weather Conditions

Current conditions at

Chicago, Chicago Midway Airport (KMDW)

Lat: 41.78°NLon: 87.76°WElev: 617ft.

Light Rain Fog/Mist

69°F

21°C

Humidity 96%
Wind Speed E 6 mph
Barometer 29.95 in (1013.5 mb)
Dewpoint 68°F (20°C)
Visibility 5.00 mi
Last update 19 Sep 9:53 pm CDT
Extended Forecast for

Chicago IL

Flood Watch September 20, 12:40am until September 20, 07:00am
Click here for hazard details and duration
Flood Watch
  •  
    Flood Watch September 20, 12:40am until September 20, 07:00am

    NOW until 7:00am Sun

    Flood Watch

  • Overnight

    Low: 69 °F

    Heavy Rain
    and Patchy
    Fog

  • Sunday

    Sunday: Showers and possibly a thunderstorm before 4pm, then a chance of showers. Patchy fog before 10am. Temperature falling to around 64 by 4pm. Breezy, with a northeast wind 10 to 20 mph, with gusts as high as 25 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.

    High: 68 °F⇓

    T-storms and
    Patchy Fog
    then Showers
    Likely and
    Breezy

  • Sunday Night

    Sunday Night: A 30 percent chance of showers, mainly before 7pm. Mostly cloudy, with a low around 58. East northeast wind around 15 mph, with gusts as high as 25 mph.

    Low: 58 °F

    Chance
    Showers then
    Mostly Cloudy

  • Monday

    Monday: A 40 percent chance of showers. Cloudy, with a high near 65. East northeast wind around 15 mph, with gusts as high as 25 mph.

    High: 65 °F

    Chance
    Showers

  • Monday Night

    Monday Night: A 20 percent chance of showers after 1am. Cloudy, with a low around 55. East northeast wind 10 to 15 mph, with gusts as high as 25 mph.

    Low: 55 °F

    Cloudy then
    Slight Chance
    Showers

  • Tuesday

    Tuesday: A 20 percent chance of showers. Mostly cloudy, with a high near 64.

    High: 64 °F

    Slight Chance
    Showers

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 56.

    Low: 56 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly cloudy, with a high near 64.

    High: 64 °F

    Mostly Cloudy

Detailed Forecast

Overnight
Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. Patchy fog. Steady temperature around 69. East southeast wind around 5 mph becoming north. Winds could gust as high as 10 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.
Sunday
Showers and possibly a thunderstorm before 4pm, then a chance of showers. Patchy fog before 10am. Temperature falling to around 64 by 4pm. Breezy, with a northeast wind 10 to 20 mph, with gusts as high as 25 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.
Sunday Night
A 30 percent chance of showers, mainly before 7pm. Mostly cloudy, with a low around 58. East northeast wind around 15 mph, with gusts as high as 25 mph.
Monday
A 40 percent chance of showers. Cloudy, with a high near 65. East northeast wind around 15 mph, with gusts as high as 25 mph.
Monday Night
A 20 percent chance of showers after 1am. Cloudy, with a low around 55. East northeast wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday
A 20 percent chance of showers. Mostly cloudy, with a high near 64.
Tuesday Night
Mostly cloudy, with a low around 56.
Wednesday
Mostly cloudy, with a high near 64.
Wednesday Night
Mostly cloudy, with a low around 56.
Thursday
Partly sunny, with a high near 66.
Thursday Night
Mostly cloudy, with a low around 57.
Friday
Partly sunny, with a high near 69.
Friday Night
Partly cloudy, with a low around 58.
Saturday
Mostly sunny, with a high near 71.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Chicago IL
 41.84°N 87.68°W
Last Update:
11:56 pm CDT Sep 19, 2026
Forecast Valid:
12am CDT Sep 20, 2026-6pm CDT Sep 26, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation