St. Marys, PA Weather & Growing Conditions
Tonight
51°F
Partly Cloudy
Partly cloudy, with a low around 51. Northeast wind around 5 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 51°F | Partly Cloudy | 5 mph NE | 1% |
| Saturday | 69°F | Partly Sunny | 5 mph E | 4% |
| Saturday Night | 58°F | Showers And Thunderstorms | 7 mph SE | 82% |
| Sunday | 69°F | Showers And Thunderstorms | 7 mph SW | 95% |
| Sunday Night | 52°F | Rain Showers Likely | 7 mph N | 65% |
| Monday | 63°F | Chance Rain Showers | 8 mph NE | 27% |
| Monday Night | 50°F | Rain Showers Likely | 9 mph E | 55% |
| Tuesday | 58°F | Rain Showers Likely | 9 mph E | 61% |
| Tuesday Night | 47°F | Rain Showers Likely | 9 to 14 mph E | 59% |
| Wednesday | 56°F | Rain Showers Likely | 10 mph E | 56% |
| Wednesday Night | 47°F | Chance Showers And Thunderstorms | 9 mph E | 53% |
| Thursday | 58°F | Chance Showers And Thunderstorms | 7 mph E | 53% |
| Thursday Night | 47°F | Chance Rain Showers | 6 mph NE | 40% |
| Friday | 65°F | Slight Chance Rain Showers then Partly Sunny | 6 mph N | 16% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for St. Marys, PA
Last spring frost
May 7
First fall frost
Oct 15
Growing season
160 days
Hardiness zone
6a
Explore more for St. Marys, PA: full frost dates · planting calendar · Pennsylvania frost dates
Climate data from the nearest NOAA station, Emporium, Pa (12.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.