Lebanon, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Lebanon, a city in St. Clair County, Illinois.
This Afternoon
73°F
Rain
Rain and a slight chance of thunderstorms. Cloudy. High near 73, with temperatures falling to around 69 in the afternoon. South wind around 21 mph, with gusts as high as 29 mph. Chance of precipitation is 90%.
7-day forecast for Lebanon
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 73°F | Rain | 21 mph S | 91% |
| Tonight | 55°F | Rain | 8 to 17 mph S | 99% |
| Wednesday | 65°F | Chance Rain Showers then Mostly Cloudy | 7 to 14 mph W | 12% |
| Wednesday Night | 43°F | Partly Cloudy | 5 mph SW | 0% |
| Thursday | 67°F | Sunny | 5 to 12 mph W | 1% |
| Thursday Night | 44°F | Mostly Cloudy | 5 mph NW | 6% |
| Friday | 59°F | Mostly Cloudy | 5 to 12 mph NW | 7% |
| Friday Night | 39°F | Partly Cloudy | 1 to 7 mph N | 1% |
| Saturday | 56°F | Partly Sunny | 1 to 5 mph NW | 0% |
| Saturday Night | 35°F | Partly Cloudy | 1 mph NW | 0% |
| Sunday | 62°F | Sunny | 1 to 7 mph W | 7% |
| Sunday Night | 36°F | Mostly Clear | 3 mph NW | 5% |
| Monday | 66°F | Sunny | 1 to 8 mph W | 2% |
| Monday Night | 40°F | Mostly Clear | 3 mph SW | 1% |
Forecast source: National Weather Service (api.weather.gov) for Lebanon (38.601, -89.810). Updated through the day.
Growing snapshot for Lebanon
Last spring frost
Apr 12
First fall frost
Oct 20
Growing season
189 days
Hardiness zone
6b
More local growing data for Lebanon: nearby ZIP 62254 weather · frost dates · planting calendar · Illinois frost dates
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Climate data from the nearest NOAA station, Belleville Siu Rsch, Il (6.3 mi from Lebanon). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.