St. Johns, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Johns, a village in Perry County, Illinois.
Overnight
63°F
Mostly Clear
Mostly clear. Low around 63, with temperatures rising to around 67 overnight. East wind around 1 mph.
7-day forecast for St. Johns
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 63°F | Mostly Clear | 1 mph E | 0% |
| Tuesday | 87°F | Patchy Fog then Sunny | 2 mph E | 0% |
| Tuesday Night | 64°F | Mostly Clear | 1 mph ESE | 0% |
| Wednesday | 90°F | Sunny | 2 mph S | 0% |
| Wednesday Night | 69°F | Partly Cloudy | 3 mph S | 13% |
| Thursday | 89°F | Chance Showers And Thunderstorms | 5 mph SSW | 35% |
| Thursday Night | 70°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 3 mph S | 58% |
| Friday | 89°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 3 mph SW | 58% |
| Friday Night | 69°F | Chance Showers And Thunderstorms | 2 mph SSW | 45% |
| Saturday | 90°F | Chance Showers And Thunderstorms | 3 mph SSW | 45% |
| Saturday Night | 71°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 2 mph SSW | 15% |
| Sunday | 92°F | Sunny | 3 to 8 mph SSW | 7% |
| Sunday Night | 72°F | Mostly Clear | 5 to 8 mph SSW | 5% |
| Monday | 94°F | Sunny | 5 to 8 mph SSW | 5% |
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 Aug 4, 2026.