Lebanon, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Lebanon, a city in St. Clair County, Illinois.
Today
87°F
Sunny
Sunny, with a high near 87. Southeast wind around 5 mph.
7-day forecast for Lebanon
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 87°F | Sunny | 5 mph SE | 0% |
| Tonight | 67°F | Mostly Clear | 1 to 5 mph SE | 0% |
| Wednesday | 90°F | Sunny | 1 to 5 mph S | 6% |
| Wednesday Night | 71°F | Slight Chance Showers And Thunderstorms | 6 mph S | 62% |
| Thursday | 87°F | Showers And Thunderstorms Likely | 6 mph S | 72% |
| Thursday Night | 70°F | Chance Showers And Thunderstorms | 3 mph SE | 48% |
| Friday | 87°F | Chance Showers And Thunderstorms | 3 mph SW | 48% |
| Friday Night | 70°F | Chance Showers And Thunderstorms | 2 mph SW | 36% |
| Saturday | 89°F | Chance Showers And Thunderstorms | 0 to 5 mph S | 36% |
| Saturday Night | 72°F | Partly Cloudy | 6 mph S | 10% |
| Sunday | 91°F | Sunny | 3 to 8 mph S | 7% |
| Sunday Night | 74°F | Mostly Clear | 5 to 8 mph S | 4% |
| Monday | 93°F | Sunny | 5 to 9 mph S | 4% |
| Monday Night | 75°F | Slight Chance Showers And Thunderstorms | 8 mph S | 15% |
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 Aug 4, 2026.