Mount Vernon, IL Weather & Growing Conditions
Overnight
71°F
Mostly Clear
Mostly clear. Low around 71, with temperatures rising to around 73 overnight. South wind around 1 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 71°F | Mostly Clear | 1 mph S | 2% |
| Saturday | 99°F | Sunny | 1 to 7 mph SW | 5% |
| Saturday Night | 72°F | Partly Cloudy | 3 mph SSW | 2% |
| Sunday | 96°F | Mostly Sunny | 2 to 6 mph W | 1% |
| Sunday Night | 67°F | Mostly Cloudy then Chance Showers And Thunderstorms | 7 mph NNE | 47% |
| Monday | 83°F | Showers And Thunderstorms Likely | 5 to 12 mph NE | 63% |
| Monday Night | 59°F | Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms | 5 to 12 mph NNE | 63% |
| Tuesday | 75°F | Chance Showers And Thunderstorms | 7 to 12 mph NNE | 34% |
| Tuesday Night | 55°F | Slight Chance Rain Showers then Partly Cloudy | 3 to 12 mph N | 15% |
| Wednesday | 76°F | Mostly Sunny | 5 to 10 mph N | 3% |
| Wednesday Night | 55°F | Partly Cloudy | 2 to 9 mph N | 1% |
| Thursday | 77°F | Mostly Sunny | 2 to 9 mph N | 2% |
| Thursday Night | 56°F | Partly Cloudy | 1 to 8 mph NNE | 3% |
| Friday | 79°F | Mostly Sunny | 2 to 9 mph NNE | 3% |
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 Sep 19, 2026.