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

Excessive Rainfall and Significant Flooding in the Upper Midwest This Weekend

Heavy to excessive rainfall is expected over the weekend across eastern Iowa, northern Missouri, northwest Illinois and southern Wisconsin. Numerous flash floods, some with significant impacts, are expected in these areas. Heaviest rainfall will occur overnight Saturday and Sunday, so be sure to have multiple ways to receive warnings. Read More >

Hazardous Weather Conditions

Current conditions at

Lewis University Airport (KLOT)

Lat: 41.6°NLon: 88.1°WElev: 669ft.

A Few Clouds

91°F

33°C

Humidity 63%
Wind Speed S 17 G 23 mph
Barometer 29.99 in
Dewpoint 77°F (25°C)
Visibility 10.00 mi
Heat Index104°F (40°C)
Last update 9 Aug 4:45 pm CDT
Extended Forecast for

Lemont IL

  • Tonight

    Tonight: Partly cloudy, with a low around 74. South wind 5 to 15 mph, with gusts as high as 25 mph.

    Low: 74 °F

    Partly Cloudy

  • Sunday

    Sunday: A 40 percent chance of showers and thunderstorms, mainly after 1pm. Mostly cloudy, with a high near 87. South southwest wind 5 to 15 mph, with gusts as high as 25 mph.

    High: 87 °F

    Chance
    T-storms

  • Sunday Night

    Sunday Night: A 40 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 72. South wind 5 to 10 mph.

    Low: 72 °F

    Chance
    T-storms

  • Monday

    Monday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 86. South southwest wind 5 to 10 mph, with gusts as high as 15 mph. Chance of precipitation is 60%.

    High: 86 °F

    Chance
    Showers then
    Showers
    Likely

  • Monday Night

    Monday Night: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 71. South southwest wind around 5 mph, with gusts as high as 10 mph.

    Low: 71 °F

    Chance
    T-storms

  • Tuesday

    Tuesday: A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 85.

    High: 85 °F

    Chance
    Showers then
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A slight chance of showers and thunderstorms. Partly cloudy, with a low around 69. Chance of precipitation is 20%.

    Low: 69 °F

    Slight Chance
    T-storms

  • Wednesday

    Wednesday: A chance of showers after 1pm. Mostly sunny, with a high near 86.

    High: 86 °F

    Mostly Sunny
    then Chance
    Showers

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 68.

    Low: 68 °F

    Partly Cloudy

Detailed Forecast

Tonight
Partly cloudy, with a low around 74. South wind 5 to 15 mph, with gusts as high as 25 mph.
Sunday
A 40 percent chance of showers and thunderstorms, mainly after 1pm. Mostly cloudy, with a high near 87. South southwest wind 5 to 15 mph, with gusts as high as 25 mph.
Sunday Night
A 40 percent chance of showers and thunderstorms, mainly after 1am. Mostly cloudy, with a low around 72. South wind 5 to 10 mph.
Monday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 1pm. Partly sunny, with a high near 86. South southwest wind 5 to 10 mph, with gusts as high as 15 mph. Chance of precipitation is 60%.
Monday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 71. South southwest wind around 5 mph, with gusts as high as 10 mph.
Tuesday
A 50 percent chance of showers and thunderstorms. Partly sunny, with a high near 85.
Tuesday Night
A slight chance of showers and thunderstorms. Partly cloudy, with a low around 69. Chance of precipitation is 20%.
Wednesday
A chance of showers after 1pm. Mostly sunny, with a high near 86.
Wednesday Night
Partly cloudy, with a low around 68.
Thursday
Mostly sunny, with a high near 86.
Thursday Night
Partly cloudy, with a low around 69.
Friday
Mostly sunny, with a high near 88.
Friday Night
Partly cloudy, with a low around 71.
Saturday
Mostly sunny, with a high near 90.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Lemont IL
 41.67°N 87.98°W
Last Update:
5:06 pm CDT Aug 9, 2025
Forecast Valid:
5pm CDT Aug 9, 2025-6pm CDT Aug 16, 2025
 
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