St. Marys, OH Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Marys, a city in Auglaize County, Ohio.
Overnight
55°F
Clear
Clear, with a low around 55. Southeast wind around 2 mph.
7-day forecast for St. Marys
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 55°F | Clear | 2 mph SE | 0% |
| Tuesday | 82°F | Sunny | 1 mph E | 0% |
| Tuesday Night | 61°F | Mostly Clear | 0 mph | 1% |
| Wednesday | 84°F | Sunny | 0 to 3 mph NW | 0% |
| Wednesday Night | 65°F | Mostly Clear | 0 to 3 mph SW | 5% |
| Thursday | 84°F | Mostly Sunny then Chance Showers And Thunderstorms | 2 to 6 mph SW | 52% |
| Thursday Night | 66°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 mph SW | 69% |
| Friday | 82°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 2 to 6 mph SW | 69% |
| Friday Night | 65°F | Chance Showers And Thunderstorms | 5 mph SW | 51% |
| Saturday | 84°F | Partly Sunny then Slight Chance Showers And Thunderstorms | 2 to 7 mph SW | 18% |
| Saturday Night | 67°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 2 to 6 mph SW | 18% |
| Sunday | 86°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 to 12 mph SW | 15% |
| Sunday Night | 69°F | Chance Showers And Thunderstorms | 7 to 10 mph SW | 25% |
| Monday | 86°F | Chance Rain Showers | 8 to 12 mph SW | 31% |
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 Aug 4, 2026.