St. Marys, PA Weather & Growing Conditions
This Afternoon
80°F
Sunny
Sunny, with a high near 80. South wind around 2 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 80°F | Sunny | 2 mph S | 0% |
| Tonight | 57°F | Mostly Clear then Patchy Fog | 3 mph SE | 0% |
| Wednesday | 80°F | Patchy Fog then Slight Chance Showers And Thunderstorms | 1 to 6 mph SE | 19% |
| Wednesday Night | 65°F | Chance Showers And Thunderstorms then Patchy Fog | 0 to 5 mph S | 49% |
| Thursday | 80°F | Patchy Fog | 1 to 6 mph S | 84% |
| Thursday Night | 65°F | Showers And Thunderstorms | 0 to 5 mph SW | 84% |
| Friday | 79°F | Showers And Thunderstorms | 0 to 5 mph SW | 83% |
| Friday Night | 62°F | Showers And Thunderstorms then Chance Showers And Thunderstorms | 0 to 3 mph SW | 83% |
| Saturday | 80°F | Showers And Thunderstorms Likely | 1 to 7 mph SW | 58% |
| Saturday Night | 61°F | Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms | 0 to 5 mph SW | 58% |
| Sunday | 82°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 2 to 8 mph SW | 20% |
| Sunday Night | 63°F | Slight Chance Showers And Thunderstorms | 3 to 7 mph SW | 21% |
| Monday | 82°F | Chance Showers And Thunderstorms | 9 mph W | 45% |
| Monday Night | 61°F | Chance Showers And Thunderstorms | 3 to 8 mph W | 45% |
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 (1.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.