Harman US

Round Lake, IL Weather & Growing Conditions

Tonight
60°F
Slight Chance Rain Showers then Showers And Thunderstorms Likely
A slight chance of rain showers before midnight, then showers and thunderstorms likely. Mostly cloudy, with a low around 60. East wind 10 to 15 mph. Chance of precipitation is 70%. New rainfall amounts between a half and three quarters of an inch possible.

7-day forecast

WhenTempForecastWindPrecip
Tonight 60°F Slight Chance Rain Showers then Showers And Thunderstorms Likely 10 to 15 mph E 73%
Saturday 75°F Showers And Thunderstorms then Showers And Thunderstorms Likely 10 to 15 mph ESE 96%
Saturday Night 62°F Showers And Thunderstorms Likely then Showers And Thunderstorms 5 to 10 mph NE 78%
Sunday 67°F Showers And Thunderstorms Likely 10 to 20 mph NE 71%
Sunday Night 54°F Chance Rain Showers 15 mph NE 43%
Monday 64°F Chance Rain Showers 15 mph ENE 38%
Monday Night 50°F Chance Rain Showers 10 to 15 mph ENE 38%
Tuesday 62°F Slight Chance Rain Showers 10 to 15 mph NE 20%
Tuesday Night 50°F Slight Chance Rain Showers then Mostly Cloudy 5 to 10 mph NE 16%
Wednesday 64°F Partly Sunny 5 to 10 mph NE 11%
Wednesday Night 50°F Mostly Cloudy 0 to 5 mph NNE 4%
Thursday 67°F Partly Sunny 0 to 5 mph NNE 5%
Thursday Night 51°F Mostly Cloudy 0 to 5 mph N 4%
Friday 69°F Mostly Sunny 0 to 5 mph NNE 4%

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

Growing snapshot for Round Lake, IL

Last spring frost
Apr 24
First fall frost
Oct 23
Growing season
180 days
Hardiness zone
5b

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

Climate data from the nearest NOAA station, Lake Villa 2Ne, Il (5.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.