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

Heat in the Central U.S.; Heavy Rain Possible for South Texas; Monitoring Erin Tropical Impacts

Hot temperatures are forecast over the Plains and into the lower Mississippi River Valley Friday where Heat Advisories have been issued. Heavy rain from a disturbance in the western Gulf could bring flooding to south Texas. Erin could bring tropical storm conditions and heavy rain to Puerto Rico and the USVI this weekend with dangerous surf and rip currents impacting the western Atlantic Basin. Read More >

Hazardous Weather Conditions

Current conditions at

Decatur Airport (KDEC)

Lat: 39.83°NLon: 88.87°WElev: 670ft.

Fair

70°F

21°C

Humidity 93%
Wind Speed Calm
Barometer 30.08 in (1017.8 mb)
Dewpoint 68°F (20°C)
Visibility 9.00 mi
Last update 15 Aug 4:54 am CDT
Extended Forecast for

Harristown IL

  • Today

    Today: Sunny, with a high near 92. Heat index values as high as 101. Light and variable wind becoming south around 6 mph in the morning.

    High: 92 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 72. Southeast wind 3 to 5 mph.

    Low: 72 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny and hot, with a high near 95. Heat index values as high as 106. Southwest wind 5 to 7 mph.

    High: 95 °F

    Hot

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 74. South wind 3 to 5 mph.

    Low: 74 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny and hot, with a high near 96. Calm wind becoming south southwest around 5 mph in the morning.

    High: 96 °F

    Hot

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 74. South wind 3 to 5 mph.

    Low: 74 °F

    Mostly Clear

  • Monday

    Monday: Sunny and hot, with a high near 96. Southwest wind around 6 mph.

    High: 96 °F

    Hot

  • Monday Night

    Monday Night: Mostly clear, with a low around 74.

    Low: 74 °F

    Mostly Clear

  • Tuesday

    Tuesday: Mostly sunny, with a high near 94.

    High: 94 °F

    Mostly Sunny

Detailed Forecast

Today
Sunny, with a high near 92. Heat index values as high as 101. Light and variable wind becoming south around 6 mph in the morning.
Tonight
Mostly clear, with a low around 72. Southeast wind 3 to 5 mph.
Saturday
Mostly sunny and hot, with a high near 95. Heat index values as high as 106. Southwest wind 5 to 7 mph.
Saturday Night
Mostly clear, with a low around 74. South wind 3 to 5 mph.
Sunday
Sunny and hot, with a high near 96. Calm wind becoming south southwest around 5 mph in the morning.
Sunday Night
Mostly clear, with a low around 74. South wind 3 to 5 mph.
Monday
Sunny and hot, with a high near 96. Southwest wind around 6 mph.
Monday Night
Mostly clear, with a low around 74.
Tuesday
Mostly sunny, with a high near 94.
Tuesday Night
A 30 percent chance of showers and thunderstorms before 1am. Partly cloudy, with a low around 71.
Wednesday
Mostly sunny, with a high near 86.
Wednesday Night
Partly cloudy, with a low around 67.
Thursday
Mostly sunny, with a high near 86.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Harristown IL
 39.82°N 89.06°W (Elev. 600 ft)
Last Update:
4:40 am CDT Aug 15, 2025
Forecast Valid:
5am CDT Aug 15, 2025-6pm CDT Aug 21, 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