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

Milwaukee-Timmerman (KMWC)

Lat: 43.11°NLon: 88.03°WElev: 735ft.

Overcast

73°F

23°C

Humidity 94%
Wind Speed Calm
Barometer 30.01 in
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Last update 9 Aug 7:45 pm CDT
Extended Forecast for

Lannon WI

Flood Watch August 9, 08:29pm until August 11, 07:00am
Click here for hazard details and duration
Flood Watch
  •  
    Flood Watch August 9, 08:29pm until August 11, 07:00am

    NOW until 7:00am Mon

    Flood Watch

  • Tonight

    Low: 71 °F

    Heavy Rain

  • Sunday

    Sunday: Scattered showers and thunderstorms before 1pm, then showers likely and possibly a thunderstorm between 1pm and 4pm, then scattered showers and thunderstorms after 4pm. Mostly cloudy, with a high near 80. South wind 5 to 10 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

    High: 80 °F

    Showers
    Likely

  • Sunday Night

    Sunday Night: Scattered showers and thunderstorms, then showers likely and possibly a thunderstorm after 7pm. Mostly cloudy, with a low around 69. Southwest wind around 5 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 69 °F

    Showers
    Likely

  • Monday

    Monday: Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 81. Southwest wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

    High: 81 °F

    Showers
    Likely

  • Monday Night

    Monday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 67. Southwest wind around 5 mph becoming calm in the evening. Chance of precipitation is 40%.

    Low: 67 °F

    Chance
    T-storms then
    Chance
    Showers

  • Tuesday

    Tuesday: A chance of showers, with thunderstorms also possible after 10am. Partly sunny, with a high near 84. Southwest wind around 5 mph. Chance of precipitation is 30%.

    High: 84 °F

    Chance
    Showers

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 65. West wind around 5 mph becoming calm in the evening.

    Low: 65 °F

    Partly Cloudy

  • Wednesday

    Wednesday: A 20 percent chance of showers after 1pm. Sunny, with a high near 82. Calm wind becoming northwest around 5 mph in the afternoon.

    High: 82 °F

    Sunny then
    Slight Chance
    Showers

Detailed Forecast

Tonight
Scattered showers and thunderstorms before 10pm, then showers likely and possibly a thunderstorm between 10pm and 1am, then scattered showers and thunderstorms after 1am. Some of the storms could produce heavy rainfall. Mostly cloudy, with a low around 71. South wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts between three quarters and one inch possible.
Sunday
Scattered showers and thunderstorms before 1pm, then showers likely and possibly a thunderstorm between 1pm and 4pm, then scattered showers and thunderstorms after 4pm. Mostly cloudy, with a high near 80. South wind 5 to 10 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Sunday Night
Scattered showers and thunderstorms, then showers likely and possibly a thunderstorm after 7pm. Mostly cloudy, with a low around 69. Southwest wind around 5 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
Monday
Showers likely and possibly a thunderstorm. Mostly cloudy, with a high near 81. Southwest wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Monday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 67. Southwest wind around 5 mph becoming calm in the evening. Chance of precipitation is 40%.
Tuesday
A chance of showers, with thunderstorms also possible after 10am. Partly sunny, with a high near 84. Southwest wind around 5 mph. Chance of precipitation is 30%.
Tuesday Night
Partly cloudy, with a low around 65. West wind around 5 mph becoming calm in the evening.
Wednesday
A 20 percent chance of showers after 1pm. Sunny, with a high near 82. Calm wind becoming northwest around 5 mph in the afternoon.
Wednesday Night
Mostly clear, with a low around 63.
Thursday
A 20 percent chance of showers. Mostly sunny, with a high near 81.
Thursday Night
Mostly clear, with a low around 65.
Friday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 85.
Friday Night
Partly cloudy, with a low around 69.
Saturday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 87.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Lannon WI
 43.16°N 88.17°W (Elev. 899 ft)
Last Update:
7:57 pm CDT Aug 9, 2025
Forecast Valid:
8pm 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