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

Dangerous Heat in the East; Critical Fire Weather in the Southwest

Dangerous, record-breaking heat will intensify across most of the central and eastern U.S this week. Heat indices will likely exceed 100 degrees. Heat is likely to continue across the eastern U.S. through the Independence Day holiday weekend. Critical fire weather conditions will continue today and likely Tuesday across portions of the Four Corners and northern High Plains. Read More >

Hazardous Weather Conditions

Current conditions at

Grinnell Municipal Airfield (KGGI)

Lat: 41.71°NLon: 92.73°WElev: 1007ft.

Partly Cloudy

90°F

32°C

Humidity 64%
Wind Speed S 18 G 28 mph
Barometer 29.79 in
Dewpoint 76°F (24°C)
Visibility 10.00 mi
Heat Index102°F (39°C)
Last update 29 Jun 2:15 pm CDT
Extended Forecast for

Sully IA

Extreme Heat Warning June 29, 02:50pm until June 30, 09:00pm
Click here for hazard details and duration
Extreme Heat Warning
  •  
    Extreme Heat Warning June 29, 02:50pm until June 30, 09:00pm

    NOW until 9:00pm Tue

    Extreme Heat Warning

  • This Afternoon

    High: 93 °F

    Sunny and
    Windy

  • Tonight

    Tonight: Mostly cloudy, then gradually becoming mostly clear, with a low around 76. Breezy, with a south wind 11 to 20 mph, with gusts as high as 29 mph.

    Low: 76 °F

    Mostly Cloudy
    and Breezy
    then Partly
    Cloudy

  • Tuesday

    Tuesday: Sunny, with a high near 94. Heat index values as high as 103. Breezy, with a south southwest wind 13 to 17 mph, with gusts as high as 26 mph.

    High: 94 °F

    Sunny and
    Breezy

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 74. South southwest wind 11 to 13 mph, with gusts as high as 23 mph.

    Low: 74 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Sunny, with a high near 93. Breezy, with a south southwest wind 10 to 17 mph, with gusts as high as 26 mph.

    High: 93 °F

    Sunny then
    Sunny and
    Breezy

  • Wednesday Night

    Wednesday Night: A 20 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 75.

    Low: 75 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

  • Thursday

    Thursday: A 30 percent chance of showers and thunderstorms, mainly before 1pm. Mostly sunny, with a high near 92.

    High: 92 °F

    Chance
    T-storms then
    Chance
    Showers

  • Thursday Night

    Thursday Night: A 40 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 73.

    Low: 73 °F

    Chance
    T-storms

Detailed Forecast

This Afternoon
Sunny, with a high near 93. Heat index values as high as 103. Windy, with a south wind around 22 mph, with gusts as high as 30 mph.
Tonight
Mostly cloudy, then gradually becoming mostly clear, with a low around 76. Breezy, with a south wind 11 to 20 mph, with gusts as high as 29 mph.
Tuesday
Sunny, with a high near 94. Heat index values as high as 103. Breezy, with a south southwest wind 13 to 17 mph, with gusts as high as 26 mph.
Tuesday Night
Partly cloudy, with a low around 74. South southwest wind 11 to 13 mph, with gusts as high as 23 mph.
Wednesday
Sunny, with a high near 93. Breezy, with a south southwest wind 10 to 17 mph, with gusts as high as 26 mph.
Wednesday Night
A 20 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 75.
Thursday
A 30 percent chance of showers and thunderstorms, mainly before 1pm. Mostly sunny, with a high near 92.
Thursday Night
A 40 percent chance of showers and thunderstorms, mainly after 1am. Partly cloudy, with a low around 73.
Friday
Mostly sunny, with a high near 91.
Friday Night
Partly cloudy, with a low around 71.
Independence Day
Mostly sunny, with a high near 91.
Saturday Night
A 50 percent chance of showers and thunderstorms. Partly cloudy, with a low around 70.
Sunday
A 40 percent chance of showers and thunderstorms. Partly sunny, with a high near 88.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Sully IA
 41.58°N 92.84°W
Last Update:
1:27 pm CDT Jun 29, 2026
Forecast Valid:
2pm CDT Jun 29, 2026-6pm CDT Jul 5, 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