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 / Wheeling, Pal-Waukee Airport (KPWK)

Lat: 42.12°NLon: 87.9°WElev: 646ft.

Thunderstorm Light Rain Fog/Mist

67°F

19°C

Humidity 100%
Wind Speed Calm
Barometer 29.92 in (1012.9 mb)
Dewpoint 67°F (19°C)
Visibility 2.50 mi
Last update 20 Sep 2:52 am CDT
Extended Forecast for

Forest Lake IL

Flood Watch September 20, 03:32am until September 20, 01:00pm
Click here for hazard details and duration
Flood Watch
  •  
    Flood Watch September 20, 03:32am until September 20, 01:00pm

    NOW until 1:00pm Sun

    Flood Watch

  • Overnight

    Low: 64 °F

    Heavy Rain
    and Patchy
    Fog

  • Sunday

    Sunday: Showers and thunderstorms before 1pm, then a chance of showers. Some of the storms could produce heavy rainfall. Patchy fog before 10am. High near 68. Northeast wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.

    High: 68 °F

    Heavy Rain
    and Patchy
    Fog then
    Chance
    Showers

  • Sunday Night

    Sunday Night: A 20 percent chance of showers after 2am. Cloudy, with a low around 57. East northeast wind around 15 mph, with gusts as high as 25 mph.

    Low: 57 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Monday

    Monday: A 30 percent chance of showers, mainly before 8am. Cloudy, with a high near 64. East northeast wind around 15 mph, with gusts as high as 25 mph.

    High: 64 °F

    Chance
    Showers

  • Monday Night

    Monday Night: A 20 percent chance of showers. Mostly cloudy, with a low around 53. East northeast wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 53 °F

    Slight Chance
    Showers

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 62.

    High: 62 °F

    Mostly Cloudy

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 51.

    Low: 51 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Partly sunny, with a high near 63.

    High: 63 °F

    Partly Sunny

Detailed Forecast

Overnight
Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. Patchy fog. Low around 64. Northeast wind around 5 mph, with gusts as high as 10 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.
Sunday
Showers and thunderstorms before 1pm, then a chance of showers. Some of the storms could produce heavy rainfall. Patchy fog before 10am. High near 68. Northeast wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Sunday Night
A 20 percent chance of showers after 2am. Cloudy, with a low around 57. East northeast wind around 15 mph, with gusts as high as 25 mph.
Monday
A 30 percent chance of showers, mainly before 8am. Cloudy, with a high near 64. East northeast wind around 15 mph, with gusts as high as 25 mph.
Monday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 53. East northeast wind 10 to 15 mph, with gusts as high as 20 mph.
Tuesday
Mostly cloudy, with a high near 62.
Tuesday Night
Partly cloudy, with a low around 51.
Wednesday
Partly sunny, with a high near 63.
Wednesday Night
Mostly cloudy, with a low around 51.
Thursday
Partly sunny, with a high near 65.
Thursday Night
Mostly cloudy, with a low around 51.
Friday
Mostly sunny, with a high near 67.
Friday Night
Partly cloudy, with a low around 50.
Saturday
Mostly sunny, with a high near 70.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Forest Lake IL
 42.2°N 88.06°W
Last Update:
2:46 am CDT Sep 20, 2026
Forecast Valid:
3am 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