Harman US

Royalton, IL Weather & Growing Conditions

Tonight
71°F
Slight Chance Showers And Thunderstorms then Partly Cloudy
A slight chance of showers and thunderstorms before 10pm. Partly cloudy. Low around 71, with temperatures rising to around 74 overnight. Southeast wind around 2 mph. Chance of precipitation is 20%.

7-day forecast

WhenTempForecastWindPrecip
Tonight 71°F Slight Chance Showers And Thunderstorms then Partly Cloudy 2 mph SE 16%
Saturday 98°F Sunny 2 to 8 mph SW 5%
Saturday Night 73°F Partly Cloudy 5 mph SSW 1%
Sunday 97°F Sunny 3 to 8 mph WSW 9%
Sunday Night 69°F Mostly Cloudy then Slight Chance Showers And Thunderstorms 5 mph NNE 22%
Monday 87°F Chance Showers And Thunderstorms 5 to 10 mph N 48%
Monday Night 62°F Chance Showers And Thunderstorms 6 to 12 mph NNE 48%
Tuesday 76°F Slight Chance Showers And Thunderstorms then Partly Sunny 8 to 13 mph N 18%
Tuesday Night 57°F Partly Cloudy 5 to 13 mph N 7%
Wednesday 75°F Mostly Sunny 6 to 10 mph N 2%
Wednesday Night 56°F Partly Cloudy 3 to 9 mph NNE 2%
Thursday 76°F Mostly Sunny 3 to 10 mph NNE 2%
Thursday Night 58°F Partly Cloudy 2 to 8 mph NNE 2%
Friday 77°F Mostly Sunny 5 to 10 mph NNE 4%

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

Growing snapshot for Royalton, IL

Last spring frost
Apr 6
First fall frost
Oct 22
Growing season
199 days
Hardiness zone
7a

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

Climate data from the nearest NOAA station, Du Quoin 4 Se, Il (7.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.