St. Peters, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Peters, a city in St. Charles County, Missouri.
Today
89°F
Patchy Fog then Sunny
Patchy fog before 8am. Sunny, with a high near 89. South wind around 3 mph.
7-day forecast for St. Peters
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 89°F | Patchy Fog then Sunny | 3 mph S | 0% |
| Tonight | 70°F | Mostly Clear | 5 mph SE | 0% |
| Wednesday | 91°F | Mostly Sunny | 5 mph S | 14% |
| Wednesday Night | 72°F | Chance Showers And Thunderstorms | 6 mph SW | 70% |
| Thursday | 87°F | Showers And Thunderstorms Likely | 5 mph S | 70% |
| Thursday Night | 70°F | Slight Chance Showers And Thunderstorms | 3 mph SE | 22% |
| Friday | 87°F | Slight Chance Showers And Thunderstorms then Partly Sunny | 2 mph SW | 22% |
| Friday Night | 71°F | Chance Showers And Thunderstorms | 2 mph S | 27% |
| Saturday | 90°F | Chance Showers And Thunderstorms then Mostly Sunny | 3 mph SW | 27% |
| Saturday Night | 73°F | Mostly Clear | 6 mph S | 6% |
| Sunday | 92°F | Sunny | 7 mph SW | 4% |
| Sunday Night | 75°F | Mostly Clear | 7 mph S | 4% |
| Monday | 93°F | Sunny | 7 mph SW | 4% |
| Monday Night | 76°F | Slight Chance Showers And Thunderstorms | 7 mph SW | 17% |
Forecast source: National Weather Service (api.weather.gov) for St. Peters (38.782, -90.604). Updated through the day.
Growing snapshot for St. Peters
Last spring frost
Apr 9
First fall frost
Oct 26
Growing season
198 days
Hardiness zone
6b
More local growing data for St. Peters: nearby ZIP 63376 weather · frost dates · planting calendar · Missouri frost dates
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Weldon Spring
Weldon Spring Heights
Wentzville
West Alton
Climate data from the nearest NOAA station, St Peters 2 Se, Mo (2.6 mi from St. Peters). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.