St. Peters, MO Weather & Growing Conditions
This Afternoon
97°F
Partly Sunny
Partly sunny, with a high near 97. Heat index values as high as 101. Southwest wind 3 to 7 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 97°F | Partly Sunny | 3 to 7 mph SW | 1% |
| Tonight | 74°F | Partly Cloudy | 5 mph SW | 1% |
| Sunday | 92°F | Partly Sunny then Chance Showers And Thunderstorms | 6 mph W | 28% |
| Sunday Night | 68°F | Showers And Thunderstorms Likely | 7 mph NE | 71% |
| Monday | 79°F | Showers And Thunderstorms Likely | 5 to 8 mph NE | 71% |
| Monday Night | 61°F | Chance Showers And Thunderstorms | 5 to 8 mph NE | 51% |
| Tuesday | 71°F | Slight Chance Rain Showers then Mostly Cloudy | 10 mph N | 22% |
| Tuesday Night | 55°F | Mostly Cloudy | 5 to 9 mph N | 1% |
| Wednesday | 73°F | Partly Sunny | 8 mph N | 0% |
| Wednesday Night | 56°F | Partly Cloudy | 2 to 7 mph N | 0% |
| Thursday | 75°F | Mostly Sunny | 5 mph N | 1% |
| Thursday Night | 59°F | Mostly Cloudy then Slight Chance Rain Showers | 3 mph NE | 15% |
| Friday | 79°F | Slight Chance Rain Showers | 2 to 6 mph NE | 19% |
| Friday Night | 60°F | Slight Chance Rain Showers then Mostly Cloudy | 5 mph NE | 19% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for St. Peters, MO
Last spring frost
Apr 9
First fall frost
Oct 26
Growing season
198 days
Hardiness zone
7a
Explore more for St. Peters, MO: full frost dates · planting calendar · Missouri frost dates
Climate data from the nearest NOAA station, St Peters 2 Se, Mo (3.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.