Lemont, IL Weather & Growing Conditions
Today
85°F
Mostly Sunny
Mostly sunny, with a high near 85. South southwest wind around 10 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 85°F | Mostly Sunny | 10 mph SSW | 2% |
| Tonight | 68°F | Mostly Cloudy then Slight Chance Showers And Thunderstorms | 5 mph SSW | 20% |
| Wednesday | 80°F | Slight Chance Showers And Thunderstorms | 5 mph SW | 63% |
| Wednesday Night | 65°F | Showers And Thunderstorms | 0 to 5 mph W | 89% |
| Thursday | 79°F | Rain Showers then Chance Showers And Thunderstorms | 0 to 5 mph SE | 75% |
| Thursday Night | 63°F | Chance Showers And Thunderstorms then Partly Cloudy | 0 to 5 mph SE | 30% |
| Friday | 82°F | Mostly Sunny | 0 to 5 mph S | 5% |
| Friday Night | 65°F | Mostly Clear | 0 to 5 mph SSW | 8% |
| Saturday | 84°F | Mostly Sunny | 5 to 10 mph SSW | 10% |
| Saturday Night | 69°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 5 to 10 mph SSW | 17% |
| Sunday | 85°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 10 to 15 mph SW | 17% |
| Sunday Night | 70°F | Chance Showers And Thunderstorms | 10 mph SSW | 40% |
| Monday | 85°F | Chance Rain Showers | 5 to 10 mph SW | 40% |
| Monday Night | 70°F | Chance Showers And Thunderstorms | 10 mph WSW | 45% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Lemont, IL
Last spring frost
Apr 19
First fall frost
Oct 22
Growing season
183 days
Hardiness zone
6a
Explore more for Lemont, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Little Red School Hse, Il (5.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.