Mount Vernon, IL Weather & Growing Conditions
This Afternoon
78°F
Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms after 5pm. Partly sunny. High near 78, with temperatures falling to around 75 in the afternoon. South wind around 22 mph, with gusts as high as 31 mph. Chance of precipitation is 20%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 78°F | Slight Chance Showers And Thunderstorms | 22 mph S | 15% |
| Tonight | 56°F | Showers And Thunderstorms | 9 to 17 mph S | 99% |
| Wednesday | 67°F | Slight Chance Rain Showers then Mostly Cloudy | 7 to 13 mph SW | 21% |
| Wednesday Night | 44°F | Partly Cloudy | 3 mph WSW | 0% |
| Thursday | 68°F | Sunny | 3 to 10 mph WSW | 0% |
| Thursday Night | 44°F | Mostly Cloudy | 2 mph WNW | 5% |
| Friday | 60°F | Mostly Cloudy | 3 to 10 mph NNW | 2% |
| Friday Night | 39°F | Partly Cloudy | 2 to 6 mph NNW | 1% |
| Saturday | 57°F | Mostly Sunny | 2 to 6 mph NNW | 0% |
| Saturday Night | 35°F | Partly Cloudy | 1 mph NW | 1% |
| Sunday | 62°F | Sunny | 0 to 8 mph W | 6% |
| Sunday Night | 35°F | Mostly Clear | 3 mph NW | 4% |
| Monday | 65°F | Sunny | 1 to 9 mph W | 3% |
| Monday Night | 39°F | Mostly Clear | 3 mph SW | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Mount Vernon, IL
Last spring frost
Apr 11
First fall frost
Oct 22
Growing season
193 days
Hardiness zone
6b
Explore more for Mount Vernon, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Mt Vernon 3 Ne, Il (2.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.