St. Marys, KS Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Marys, a city in Pottawatomie County, Kansas.
Overnight
66°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms before 4am, then showers and thunderstorms likely. Mostly cloudy, with a low around 66. North wind around 5 mph. Chance of precipitation is 50%.
7-day forecast for St. Marys
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 66°F | Chance Showers And Thunderstorms | 5 mph N | 53% |
| Sunday | 75°F | Showers And Thunderstorms Likely | 5 to 10 mph N | 58% |
| Sunday Night | 62°F | Chance Showers And Thunderstorms then Mostly Cloudy | 5 mph N | 30% |
| Monday | 72°F | Chance Rain Showers then Mostly Cloudy | 5 mph N | 25% |
| Monday Night | 55°F | Slight Chance Rain Showers then Mostly Cloudy | 5 mph N | 15% |
| Tuesday | 67°F | Partly Sunny | 5 mph NE | 7% |
| Tuesday Night | 50°F | Partly Cloudy | 5 mph E | 0% |
| Wednesday | 68°F | Mostly Sunny | 5 mph E | 1% |
| Wednesday Night | 52°F | Mostly Cloudy | 5 mph E | 9% |
| Thursday | 71°F | Chance Rain Showers | 0 to 5 mph SE | 37% |
| Thursday Night | 57°F | Chance Rain Showers | 0 to 5 mph E | 25% |
| Friday | 75°F | Chance Rain Showers | 0 to 5 mph E | 31% |
| Friday Night | 60°F | Chance Rain Showers | 5 mph E | 25% |
| Saturday | 78°F | Chance Rain Showers | 5 mph SE | 33% |
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 Sep 20, 2026.