St. Marys, KS Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Marys, a city in Pottawatomie County, Kansas.
Today
90°F
Slight Chance Rain Showers then Partly Sunny
A slight chance of rain showers between 8am and 9am. Partly sunny, with a high near 90. Southeast wind 0 to 10 mph. Chance of precipitation is 20%.
7-day forecast for St. Marys
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 90°F | Slight Chance Rain Showers then Partly Sunny | 0 to 10 mph SE | 16% |
| Tonight | 69°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 5 to 10 mph NE | 23% |
| Wednesday | 81°F | Chance Showers And Thunderstorms | 10 mph NE | 32% |
| Wednesday Night | 65°F | Chance Showers And Thunderstorms | 5 to 10 mph NE | 63% |
| Thursday | 85°F | Showers And Thunderstorms Likely then Mostly Sunny | 5 mph E | 63% |
| Thursday Night | 67°F | Chance Showers And Thunderstorms | 0 to 5 mph SE | 45% |
| Friday | 89°F | Chance Showers And Thunderstorms then Mostly Sunny | 0 to 5 mph S | 45% |
| Friday Night | 70°F | Mostly Clear | 5 mph S | 6% |
| Saturday | 93°F | Sunny | 5 to 10 mph S | 5% |
| Saturday Night | 75°F | Mostly Clear | 10 mph S | 1% |
| Sunday | 95°F | Sunny | 10 to 15 mph S | 1% |
| Sunday Night | 76°F | Mostly Clear | 10 to 15 mph S | 2% |
| Monday | 96°F | Mostly Sunny | 10 to 15 mph S | 2% |
| Monday Night | 76°F | Mostly Clear | 10 to 15 mph S | 2% |
Forecast source: National Weather Service (api.weather.gov) for St. Marys (39.194, -96.064). Updated through the day.
Growing snapshot for St. Marys
Last spring frost
Apr 18
First fall frost
Oct 19
Growing season
183 days
Hardiness zone
6b
More local growing data for St. Marys: nearby ZIP 66536 weather · frost dates · planting calendar · Kansas frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Wamego 4 W, Ks (16.1 mi from St. Marys). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.