St. Peter, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Peter, a village in Fayette County, Illinois.
Tonight
70°F
Partly Cloudy
Partly cloudy, with a low around 70. Southeast wind around 6 mph.
7-day forecast for St. Peter
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 70°F | Partly Cloudy | 6 mph SE | 13% |
| Saturday | 95°F | Sunny | 6 mph SW | 8% |
| Saturday Night | 71°F | Mostly Cloudy | 3 mph S | 3% |
| Sunday | 92°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 2 to 7 mph W | 19% |
| Sunday Night | 65°F | Chance Showers And Thunderstorms | 6 mph N | 43% |
| Monday | 80°F | Chance Rain Showers then Chance Showers And Thunderstorms | 7 to 10 mph NE | 54% |
| Monday Night | 58°F | Chance Showers And Thunderstorms | 6 to 12 mph NE | 54% |
| Tuesday | 73°F | Chance Showers And Thunderstorms then Partly Sunny | 12 mph N | 33% |
| Tuesday Night | 54°F | Mostly Cloudy | 3 to 12 mph N | 6% |
| Wednesday | 74°F | Partly Sunny | 6 to 9 mph N | 4% |
| Wednesday Night | 54°F | Partly Cloudy | 2 to 8 mph N | 4% |
| Thursday | 75°F | Mostly Sunny | 3 to 8 mph N | 2% |
| Thursday Night | 56°F | Partly Cloudy | 2 to 6 mph NE | 2% |
| Friday | 76°F | Mostly Sunny | 3 to 8 mph NE | 5% |
Forecast source: National Weather Service (api.weather.gov) for St. Peter (38.868, -88.850). Updated through the day.
Growing snapshot for St. Peter
Last spring frost
Apr 3
First fall frost
Oct 24
Growing season
202 days
Hardiness zone
6b
More local growing data for St. Peter: nearby ZIP 62880 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Brownstown 4 Sw, Il (7.2 mi from St. Peter). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.