Harman US

Harristown, IL Weather & Growing Conditions

Tonight
70°F
Partly Cloudy
Partly cloudy, with a low around 70. Southeast wind around 9 mph, with gusts as high as 17 mph.

7-day forecast

WhenTempForecastWindPrecip
Tonight 70°F Partly Cloudy 9 mph SE 4%
Saturday 91°F Slight Chance Showers And Thunderstorms then Partly Sunny 9 mph SSW 18%
Saturday Night 70°F Partly Cloudy then Slight Chance Rain Showers 8 mph SSW 23%
Sunday 86°F Chance Rain Showers 3 to 12 mph NNW 47%
Sunday Night 61°F Chance Showers And Thunderstorms 10 to 14 mph NE 68%
Monday 72°F Showers And Thunderstorms Likely 15 mph NE 68%
Monday Night 55°F Showers And Thunderstorms Likely 12 to 15 mph NE 64%
Tuesday 68°F Chance Rain Showers 15 mph NE 34%
Tuesday Night 52°F Mostly Cloudy 7 to 13 mph NNE 7%
Wednesday 71°F Partly Sunny 12 mph NNE 2%
Wednesday Night 53°F Partly Cloudy 5 to 10 mph NNE 2%
Thursday 72°F Mostly Sunny 5 to 10 mph NNE 3%
Thursday Night 55°F Partly Cloudy 3 to 9 mph NNE 5%
Friday 74°F Mostly Sunny 5 to 10 mph NNE 5%

Forecast source: National Weather Service (api.weather.gov). Updated through the day.

Growing snapshot for Harristown, IL

Last spring frost
Apr 14
First fall frost
Oct 24
Growing season
192 days
Hardiness zone
6a

Explore more for Harristown, IL: full frost dates · planting calendar · Illinois frost dates

Climate data from the nearest NOAA station, Decatur Wtp, Il (5.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.