Hazardous Weather Conditions
Current conditions at
Decatur Airport (KDEC)
Lat: 39.83°NLon: 88.87°WElev: 670ft.
A Few Clouds
84°F
29°C
| Humidity | 77% |
| Wind Speed | S 8 mph |
| Barometer | 30.04 in (1016.6 mb) |
| Dewpoint | 76°F (24°C) |
| Visibility | 10.00 mi |
| Heat Index | 93°F (34°C) |
| Last update | 15 Aug 5:54 pm CDT |
Extended Forecast for
Harristown IL
Tonight
Low: 74 °F
Partly Cloudy
then Chance
T-stormsSunday
High: 87 °F
Chance
T-stormsSunday Night
Low: 68 °F
Chance
T-storms then
Partly CloudyMonday
High: 81 °F
Mostly Sunny
Monday Night
Low: 62 °F
Mostly Clear
Tuesday
High: 83 °F
Mostly Sunny
Tuesday Night
Low: 68 °F
Partly Cloudy
then Chance
T-stormsWednesday
High: 81 °F
Chance
Showers then
Chance
T-stormsWednesday Night
Low: 62 °F
Partly Cloudy
Detailed Forecast
Tonight
A 40 percent chance of showers and thunderstorms, mainly after 2am. Mostly cloudy, with a low around 74. West southwest wind 3 to 7 mph.
Sunday
A chance of showers and thunderstorms before 2pm, then a chance of showers and thunderstorms after 3pm. Partly sunny, with a high near 87. West wind 7 to 10 mph, with gusts as high as 15 mph. Chance of precipitation is 40%.
Sunday Night
A 30 percent chance of showers and thunderstorms, mainly before 10pm. Partly cloudy, with a low around 68. Northwest wind 6 to 9 mph.
Monday
Mostly sunny, with a high near 81. North northwest wind 6 to 9 mph.
Monday Night
Mostly clear, with a low around 62. North wind around 6 mph becoming calm in the evening.
Tuesday
Mostly sunny, with a high near 83. Calm wind becoming south southwest around 6 mph in the morning.
Tuesday Night
A 40 percent chance of showers and thunderstorms after 1am. Partly cloudy, with a low around 68. South wind 3 to 7 mph.
Wednesday
A chance of showers, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 81. Chance of precipitation is 50%.
Wednesday Night
Partly cloudy, with a low around 62.
Thursday
Mostly sunny, with a high near 77.
Thursday Night
Partly cloudy, with a low around 59.
Friday
Mostly sunny, with a high near 78.
Friday Night
Partly cloudy, with a low around 61.
Saturday
Mostly sunny, with a high near 79.
Additional Forecasts and Information
Basemap Options
Click map to change the forecast location
Loading map...
Forecast AreaABOUT THIS FORECAST
Point Forecast:
Harristown IL
39.84°N 89.06°W (Elev. 699 ft)
39.84°N 89.06°W (Elev. 699 ft)
6:36 pm CDT Aug 15, 2026
6pm CDT Aug 15, 2026-6pm CDT Aug 22, 2026
Additional Resources
Radar & Satellite Image
Hourly Weather Forecast
