St. Marys, OH Weather & Growing Conditions
Overnight
56°F
Partly Cloudy
Partly cloudy, with a low around 56. East wind around 6 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 56°F | Partly Cloudy | 6 mph E | 2% |
| Saturday | 77°F | Showers And Thunderstorms Likely | 6 mph SE | 68% |
| Saturday Night | 64°F | Showers And Thunderstorms Likely | 6 mph S | 68% |
| Sunday | 76°F | Showers And Thunderstorms | 3 to 10 mph NW | 76% |
| Sunday Night | 56°F | Showers And Thunderstorms | 13 mph NE | 76% |
| Monday | 67°F | Showers And Thunderstorms Likely | 10 to 16 mph NE | 55% |
| Monday Night | 53°F | Chance Showers And Thunderstorms | 12 to 16 mph NE | 50% |
| Tuesday | 67°F | Chance Showers And Thunderstorms | 12 to 15 mph NE | 37% |
| Tuesday Night | 54°F | Chance Rain Showers | 8 to 15 mph NE | 34% |
| Wednesday | 67°F | Chance Rain Showers | 10 mph NE | 33% |
| Wednesday Night | 54°F | Slight Chance Rain Showers then Mostly Cloudy | 5 to 10 mph N | 18% |
| Thursday | 69°F | Mostly Cloudy | 6 to 9 mph N | 11% |
| Thursday Night | 53°F | Mostly Cloudy | 3 to 9 mph N | 11% |
| Friday | 70°F | Partly Sunny | 5 to 9 mph N | 5% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for St. Marys, OH
Last spring frost
Apr 27
First fall frost
Oct 19
Growing season
175 days
Hardiness zone
6a
Explore more for St. Marys, OH: full frost dates · planting calendar · Ohio frost dates
Climate data from the nearest NOAA station, Celina 3 Ne, Oh (7.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.