St. Peter, IL Weather & Growing Conditions
Today
61°F
Slight Chance Drizzle
A slight chance of drizzle before 3pm. Mostly cloudy, with a high near 61. Southwest wind 7 to 13 mph, with gusts as high as 21 mph. Chance of precipitation is 20%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 61°F | Slight Chance Drizzle | 7 to 13 mph SW | 22% |
| Tonight | 44°F | Partly Cloudy | 5 mph SW | 0% |
| Thursday | 63°F | Sunny | 5 to 12 mph W | 0% |
| Thursday Night | 44°F | Mostly Cloudy | 3 mph NW | 1% |
| Friday | 56°F | Partly Sunny | 5 to 12 mph NW | 2% |
| Friday Night | 35°F | Partly Cloudy | 2 to 7 mph N | 0% |
| Saturday | 54°F | Mostly Sunny | 5 mph N | 0% |
| Saturday Night | 33°F | Partly Cloudy | 2 mph NW | 0% |
| Sunday | 59°F | Sunny | 1 to 7 mph NW | 1% |
| Sunday Night | 34°F | Clear | 2 mph W | 1% |
| Monday | 63°F | Sunny | 0 to 6 mph SW | 0% |
| Monday Night | 39°F | Clear | 2 mph SW | 0% |
| Tuesday | 67°F | Sunny | 5 mph W | 1% |
| Tuesday Night | 40°F | Mostly Clear | 1 mph N | 2% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for St. Peter, IL
Last spring frost
Apr 3
First fall frost
Oct 24
Growing season
202 days
Hardiness zone
6b
Explore more for St. Peter, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Brownstown 4 Sw, Il (7.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.