St. Marys, OH Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Marys, a city in Auglaize County, Ohio.
This Afternoon
75°F
Mostly Sunny
Mostly sunny, with a high near 75. Northeast wind around 8 mph.
7-day forecast for St. Marys
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 75°F | Mostly Sunny | 8 mph NE | 1% |
| Tonight | 56°F | Partly Cloudy | 5 to 8 mph E | 2% |
| Saturday | 77°F | Showers And Thunderstorms Likely | 6 mph SE | 67% |
| 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 | 9 to 13 mph NE | 76% |
| Monday | 68°F | Showers And Thunderstorms Likely | 10 to 15 mph NE | 55% |
| Monday Night | 53°F | Chance Showers And Thunderstorms | 12 to 16 mph NE | 50% |
| Tuesday | 68°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 | 68°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% |
Forecast source: National Weather Service (api.weather.gov) for St. Marys (40.548, -84.392). Updated through the day.
Growing snapshot for St. Marys
Last spring frost
Apr 27
First fall frost
Oct 19
Growing season
175 days
Hardiness zone
6a
More local growing data for St. Marys: nearby ZIP 45885 weather · frost dates · planting calendar · Ohio frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Celina 3 Ne, Oh (7.7 mi from St. Marys). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 18, 2026.