Lemont, IL Weather & Growing Conditions
Today
77°F
Showers And Thunderstorms then Showers And Thunderstorms Likely
Showers and thunderstorms before noon, then showers and thunderstorms likely. Cloudy. High near 77, with temperatures falling to around 75 in the afternoon. Southeast wind 5 to 10 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 77°F | Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 10 mph SE | 100% |
| Tonight | 65°F | Showers And Thunderstorms | 5 to 10 mph S | 95% |
| Sunday | 69°F | Showers And Thunderstorms Likely | 10 to 15 mph NNE | 65% |
| Sunday Night | 56°F | Chance Rain Showers | 15 mph NE | 37% |
| Monday | 64°F | Chance Rain Showers | 15 mph ENE | 31% |
| Monday Night | 53°F | Slight Chance Rain Showers then Mostly Cloudy | 10 to 15 mph NE | 22% |
| Tuesday | 62°F | Slight Chance Rain Showers | 10 to 15 mph NE | 18% |
| Tuesday Night | 53°F | Mostly Cloudy | 10 to 15 mph NE | 9% |
| Wednesday | 64°F | Partly Sunny | 10 to 15 mph NNE | 12% |
| Wednesday Night | 54°F | Mostly Cloudy | 5 to 10 mph NNE | 4% |
| Thursday | 66°F | Partly Sunny | 5 to 10 mph NNE | 3% |
| Thursday Night | 54°F | Mostly Cloudy | 5 to 10 mph NNE | 3% |
| Friday | 70°F | Partly Sunny | 5 to 10 mph NE | 3% |
| Friday Night | 54°F | Partly Cloudy | 5 to 10 mph NE | 3% |
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 Sep 19, 2026.