St. Johns, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Johns, a village in Perry County, Illinois.
Tonight
55°F
Showers And Thunderstorms
Showers and thunderstorms. Mostly cloudy. Low around 55, with temperatures rising to around 58 overnight. South wind 8 to 16 mph, with gusts as high as 22 mph. Chance of precipitation is 100%.
7-day forecast for St. Johns
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 55°F | Showers And Thunderstorms | 8 to 16 mph S | 99% |
| Wednesday | 68°F | Partly Sunny | 6 to 12 mph WSW | 12% |
| Wednesday Night | 42°F | Partly Cloudy | 3 mph WSW | 0% |
| Thursday | 69°F | Sunny | 3 to 9 mph WSW | 0% |
| Thursday Night | 44°F | Mostly Cloudy | 3 mph WNW | 6% |
| Friday | 61°F | Partly Sunny | 3 to 12 mph NNW | 2% |
| Friday Night | 38°F | Partly Cloudy | 2 to 6 mph NNW | 1% |
| Saturday | 58°F | Partly Sunny | 2 to 6 mph NNW | 0% |
| Saturday Night | 34°F | Partly Cloudy | 1 mph NW | 1% |
| Sunday | 63°F | Sunny | 1 to 8 mph W | 5% |
| Sunday Night | 34°F | Mostly Clear | 3 mph WNW | 4% |
| Monday | 66°F | Sunny | 1 to 8 mph WSW | 2% |
| Monday Night | 38°F | Mostly Clear | 5 mph SW | 0% |
| Tuesday | 70°F | Sunny | 3 to 7 mph WSW | 1% |
Forecast source: National Weather Service (api.weather.gov) for St. Johns (38.035, -89.239). Updated through the day.
Growing snapshot for St. Johns
Last spring frost
Apr 6
First fall frost
Oct 22
Growing season
199 days
Hardiness zone
7a
More local growing data for St. Johns: nearby ZIP 62832 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Du Quoin 4 Se, Il (3.6 mi from St. Johns). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.