Vandalia, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Vandalia, a city in Fayette County, Illinois.
This Afternoon
99°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms. Sunny. High near 99, with temperatures falling to around 94 in the afternoon. Heat index values as high as 101. South wind around 2 mph. Chance of precipitation is 30%.
7-day forecast for Vandalia
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 99°F | Chance Showers And Thunderstorms | 2 mph S | 25% |
| Tonight | 70°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 5 mph SE | 23% |
| Saturday | 96°F | Mostly Sunny | 2 to 6 mph SW | 7% |
| Saturday Night | 71°F | Mostly Cloudy | 3 mph S | 5% |
| Sunday | 92°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 1 to 6 mph W | 21% |
| Sunday Night | 64°F | Chance Showers And Thunderstorms | 7 mph NE | 47% |
| Monday | 79°F | Rain Showers Likely | 5 to 9 mph NE | 58% |
| Monday Night | 57°F | Showers And Thunderstorms Likely | 6 to 12 mph NE | 56% |
| Tuesday | 73°F | Chance Showers And Thunderstorms then Partly Sunny | 10 mph NE | 28% |
| Tuesday Night | 53°F | Mostly Cloudy | 3 to 10 mph N | 5% |
| Wednesday | 74°F | Mostly Sunny | 5 to 8 mph N | 3% |
| Wednesday Night | 54°F | Partly Cloudy | 1 to 8 mph N | 3% |
| Thursday | 75°F | Mostly Sunny | 2 to 7 mph N | 3% |
| Thursday Night | 56°F | Partly Cloudy | 2 to 6 mph NE | 3% |
Forecast source: National Weather Service (api.weather.gov) for Vandalia (38.975, -89.111). Updated through the day.
Growing snapshot for Vandalia
Last spring frost
Apr 10
First fall frost
Oct 24
Growing season
196 days
Hardiness zone
6b
More local growing data for Vandalia: nearby ZIP 62471 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Vandalia, Il (1.9 mi from Vandalia). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.