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Lake Forest, IL Weather & Growing Conditions

Overnight
62°F
Showers And Thunderstorms
Showers and thunderstorms. Some of the storms could produce heavy rain. Cloudy. Low around 62, with temperatures rising to around 64 overnight. East southeast wind around 15 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.

7-day forecast

WhenTempForecastWindPrecip
Overnight 62°F Showers And Thunderstorms 15 mph ESE 97%
Saturday 75°F Showers And Thunderstorms then Showers And Thunderstorms Likely 5 to 15 mph SSE 100%
Saturday Night 61°F Showers And Thunderstorms 5 to 10 mph E 94%
Sunday 69°F Showers And Thunderstorms Likely 15 to 20 mph NNE 56%
Sunday Night 55°F Mostly Cloudy 15 to 20 mph NE 14%
Monday 65°F Slight Chance Rain Showers 15 to 20 mph ENE 19%
Monday Night 53°F Mostly Cloudy 15 to 20 mph ENE 10%
Tuesday 64°F Mostly Cloudy 15 to 20 mph NE 11%
Tuesday Night 53°F Mostly Cloudy 10 to 15 mph NE 8%
Wednesday 64°F Partly Sunny 10 to 15 mph NE 13%
Wednesday Night 54°F Mostly Cloudy 5 to 10 mph NE 6%
Thursday 66°F Partly Sunny 5 to 10 mph NNE 4%
Thursday Night 54°F Mostly Cloudy 5 mph NNE 3%
Friday 68°F Partly Sunny 5 to 10 mph NE 4%

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

Growing snapshot for Lake Forest, IL

Last spring frost
Apr 26
First fall frost
Oct 21
Growing season
176 days
Hardiness zone
6a

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

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