St. Marys, OH Weather & Growing Conditions
Overnight
62°F
Rain Showers Likely
Rain showers likely after 4am. Mostly cloudy, with a low around 62. South wind 13 to 16 mph, with gusts as high as 28 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 62°F | Rain Showers Likely | 13 to 16 mph S | 60% |
| Wednesday | 69°F | Rain Showers | 13 to 20 mph S | 99% |
| Wednesday Night | 50°F | Mostly Cloudy | 6 to 12 mph SW | 11% |
| Thursday | 63°F | Mostly Sunny | 7 to 16 mph SW | 0% |
| Thursday Night | 45°F | Mostly Cloudy | 2 to 7 mph SW | 2% |
| Friday | 58°F | Chance Light Rain | 2 to 9 mph NW | 28% |
| Friday Night | 38°F | Slight Chance Light Rain | 8 mph NW | 18% |
| Saturday | 54°F | Slight Chance Light Rain | 8 mph NW | 15% |
| Saturday Night | 33°F | Partly Cloudy | 3 mph W | 7% |
| Sunday | 56°F | Mostly Sunny then Slight Chance Light Rain | 2 to 10 mph W | 15% |
| Sunday Night | 34°F | Slight Chance Light Rain then Partly Cloudy | 5 to 8 mph W | 15% |
| Monday | 59°F | Mostly Sunny | 5 to 12 mph W | 14% |
| Monday Night | 38°F | Mostly Clear | 9 mph SW | 13% |
| Tuesday | 62°F | Mostly Sunny | 7 to 12 mph W | 3% |
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 Nov 4, 2026.