St. Marys, PA Weather & Growing Conditions
Today
73°F
Partly Sunny
Partly sunny, with a high near 73. Southeast wind 2 to 9 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 73°F | Partly Sunny | 2 to 9 mph SE | 2% |
| Tonight | 57°F | Light Rain | 9 mph S | 94% |
| Thursday | 68°F | Light Rain Likely | 7 to 12 mph SW | 65% |
| Thursday Night | 44°F | Mostly Cloudy | 1 to 5 mph SW | 1% |
| Friday | 62°F | Mostly Cloudy then Slight Chance Light Rain | 1 to 6 mph SW | 21% |
| Friday Night | 39°F | Chance Light Rain | 3 mph W | 41% |
| Saturday | 51°F | Chance Light Rain | 5 to 10 mph W | 50% |
| Saturday Night | 32°F | Chance Light Rain | 6 to 9 mph W | 46% |
| Sunday | 52°F | Slight Chance Light Rain then Partly Sunny | 12 mph W | 15% |
| Sunday Night | 30°F | Partly Cloudy then Slight Chance Light Rain | 6 to 9 mph W | 16% |
| Monday | 53°F | Chance Light Rain | 9 to 13 mph W | 25% |
| Monday Night | 30°F | Slight Chance Light Rain then Partly Cloudy | 6 to 9 mph W | 15% |
| Tuesday | 57°F | Mostly Sunny | 10 to 14 mph W | 9% |
| Tuesday Night | 29°F | Partly Cloudy | 5 to 9 mph W | 10% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for St. Marys, PA
Last spring frost
May 14
First fall frost
Oct 6
Growing season
143 days
Hardiness zone
5b
Explore more for St. Marys, PA: full frost dates · planting calendar · Pennsylvania frost dates
Climate data from the nearest NOAA station, Glen Hazel 2 Ne Dam, Pa (8.4 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.