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

Mason City Municipal Airport (KMCW)

Lat: 43.15°NLon: 93.33°WElev: 1188ft.

Fog/Mist

62°F

17°C

Humidity 96%
Wind Speed SE 6 mph
Barometer 29.92 in (1012.5 mb)
Dewpoint 61°F (16°C)
Visibility 2.50 mi
Last update 19 Sep 7:53 am CDT
Extended Forecast for

Clear Lake IA

Flood Watch September 19, 08:54am until September 19, 01:00pm
Click here for hazard details and duration
Flood Watch
  •  
    Flood Watch September 19, 08:54am until September 19, 01:00pm

    NOW until 1:00pm Sat

    Flood Watch

  • Today

    High: 72 °F

    Chance
    Showers and
    Patchy Dense
    Fog

  • Tonight

    Tonight: A slight chance of showers before 1am, then a slight chance of drizzle between 1am and 2am. Cloudy, with a low around 56. North northeast wind 9 to 11 mph. Chance of precipitation is 20%.

    Low: 56 °F

    Slight Chance
    Showers

  • Sunday

    Sunday: Mostly cloudy, with a high near 65. East northeast wind around 14 mph, with gusts as high as 22 mph.

    High: 65 °F

    Mostly Cloudy

  • Sunday Night

    Sunday Night: A 30 percent chance of showers, mainly after 1am. Mostly cloudy, with a low around 51. East northeast wind around 11 mph. New precipitation amounts of less than a tenth of an inch possible.

    Low: 51 °F

    Chance
    Showers

  • Monday

    Monday: A 40 percent chance of showers. Mostly cloudy, with a high near 61. East northeast wind around 11 mph. New precipitation amounts of less than a tenth of an inch possible.

    High: 61 °F

    Chance
    Showers

  • Monday Night

    Monday Night: A 20 percent chance of showers before 1am. Mostly cloudy, with a low around 46.

    Low: 46 °F

    Slight Chance
    Showers

  • Tuesday

    Tuesday: Mostly sunny, with a high near 60.

    High: 60 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 42.

    Low: 42 °F

    Mostly Clear

Detailed Forecast

Today
A chance of showers and thunderstorms before 4pm, then a slight chance of showers. Patchy dense fog before 11am. Otherwise, mostly cloudy, with a high near 72. East northeast wind 6 to 8 mph becoming west northwest in the morning. Chance of precipitation is 50%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tonight
A slight chance of showers before 1am, then a slight chance of drizzle between 1am and 2am. Cloudy, with a low around 56. North northeast wind 9 to 11 mph. Chance of precipitation is 20%.
Sunday
Mostly cloudy, with a high near 65. East northeast wind around 14 mph, with gusts as high as 22 mph.
Sunday Night
A 30 percent chance of showers, mainly after 1am. Mostly cloudy, with a low around 51. East northeast wind around 11 mph. New precipitation amounts of less than a tenth of an inch possible.
Monday
A 40 percent chance of showers. Mostly cloudy, with a high near 61. East northeast wind around 11 mph. New precipitation amounts of less than a tenth of an inch possible.
Monday Night
A 20 percent chance of showers before 1am. Mostly cloudy, with a low around 46.
Tuesday
Mostly sunny, with a high near 60.
Tuesday Night
Mostly clear, with a low around 42.
Wednesday
Sunny, with a high near 64.
Wednesday Night
Partly cloudy, with a low around 47.
Thursday
Partly sunny, with a high near 65.
Thursday Night
Mostly cloudy, with a low around 50.
Friday
Mostly sunny, with a high near 68.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Clear Lake IA
 43.13°N 93.37°W
Last Update:
5:17 am CDT Sep 19, 2026
Forecast Valid:
8am CDT Sep 19, 2026-6pm CDT Sep 25, 2026
 
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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