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

Grinnell Municipal Airfield (KGGI)

Lat: 41.71°NLon: 92.73°WElev: 1007ft.

Overcast

42°F

6°C

Humidity 76%
Wind Speed Calm
Barometer 30.13 in
Dewpoint 34°F (1°C)
Visibility 7.00 mi
Last update 3 Mar 6:15 pm CST
Extended Forecast for

Sully IA

  • Tonight

    Tonight: A slight chance of drizzle after 4am. Mostly cloudy, with a low around 34. Northeast wind 3 to 6 mph.

    Low: 34 °F

    Mostly Cloudy
    then Slight
    Chance
    Drizzle

  • Wednesday

    Wednesday: A chance of drizzle, mainly after 4pm. Mostly cloudy, with a high near 49. Northeast wind around 6 mph becoming calm in the afternoon.

    High: 49 °F

    Chance
    Drizzle

  • Wednesday Night

    Wednesday Night: Showers likely, mainly after midnight. Patchy dense fog after 9pm. Otherwise, cloudy, with a low around 39. Calm wind. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 39 °F

    Showers
    Likely and
    Patchy Dense
    Fog

  • Thursday

    Thursday: A 20 percent chance of showers before noon. Areas of fog before 10am. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 61. Calm wind becoming south around 6 mph in the afternoon.

    High: 61 °F

    Slight Chance
    Showers and
    Areas Fog
    then Mostly
    Sunny

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm after midnight. Mostly cloudy, with a low around 46. Southeast wind 5 to 11 mph, with gusts as high as 20 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 46 °F

    Mostly Clear
    then Showers
    Likely

  • Friday

    Friday: Showers and possibly a thunderstorm. High near 69. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.

    High: 69 °F

    Showers then
    Showers
    Likely

  • Friday Night

    Friday Night: Rain and possibly a thunderstorm before midnight, then a chance of rain. Low around 39. Chance of precipitation is 80%.

    Low: 39 °F

    Rain then
    Chance Rain

  • Saturday

    Saturday: Mostly sunny, with a high near 54.

    High: 54 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 36.

    Low: 36 °F

    Mostly Clear

Detailed Forecast

Tonight
A slight chance of drizzle after 4am. Mostly cloudy, with a low around 34. Northeast wind 3 to 6 mph.
Wednesday
A chance of drizzle, mainly after 4pm. Mostly cloudy, with a high near 49. Northeast wind around 6 mph becoming calm in the afternoon.
Wednesday Night
Showers likely, mainly after midnight. Patchy dense fog after 9pm. Otherwise, cloudy, with a low around 39. Calm wind. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Thursday
A 20 percent chance of showers before noon. Areas of fog before 10am. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 61. Calm wind becoming south around 6 mph in the afternoon.
Thursday Night
Showers likely and possibly a thunderstorm after midnight. Mostly cloudy, with a low around 46. Southeast wind 5 to 11 mph, with gusts as high as 20 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
Friday
Showers and possibly a thunderstorm. High near 69. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.
Friday Night
Rain and possibly a thunderstorm before midnight, then a chance of rain. Low around 39. Chance of precipitation is 80%.
Saturday
Mostly sunny, with a high near 54.
Saturday Night
Mostly clear, with a low around 36.
Sunday
Sunny, with a high near 63.
Sunday Night
Mostly clear, with a low around 40.
Monday
Sunny, with a high near 68.
Monday Night
Mostly clear, with a low around 48.
Tuesday
A 40 percent chance of rain. Partly sunny, with a high near 66. Breezy.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Sully IA
 41.58°N 92.84°W
Last Update:
5:26 pm CST Mar 3, 2026
Forecast Valid:
6pm CST Mar 3, 2026-6pm CDT Mar 10, 2026
 
Forecast Discussion
 
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Additional Resources

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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