St. Marys, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Marys, a city in Elk County, Pennsylvania.
Overnight
49°F
Areas Of Fog
Areas of fog. Mostly clear, with a low around 49. Wind around 0 mph.
7-day forecast for St. Marys
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 49°F | Areas Of Fog | 0 mph | 0% |
| Tuesday | 82°F | Areas Of Fog then Sunny | 0 to 3 mph SE | 0% |
| Tuesday Night | 59°F | Partly Cloudy then Patchy Fog | 3 mph SE | 0% |
| Wednesday | 82°F | Patchy Fog then Slight Chance Showers And Thunderstorms | 1 to 6 mph SE | 16% |
| Wednesday Night | 64°F | Chance Showers And Thunderstorms | 1 to 5 mph SE | 48% |
| Thursday | 83°F | Patchy Fog | 1 to 6 mph S | 85% |
| Thursday Night | 64°F | Showers And Thunderstorms | 0 to 5 mph SW | 85% |
| Friday | 82°F | Showers And Thunderstorms | 1 to 6 mph SW | 81% |
| Friday Night | 63°F | Showers And Thunderstorms then Chance Showers And Thunderstorms | 3 mph SW | 81% |
| Saturday | 81°F | Chance Rain Showers then Chance Showers And Thunderstorms | 2 to 7 mph SW | 49% |
| Saturday Night | 63°F | Chance Showers And Thunderstorms | 1 to 5 mph W | 49% |
| Sunday | 83°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 2 to 8 mph SW | 18% |
| Sunday Night | 65°F | Slight Chance Showers And Thunderstorms | 5 to 8 mph SW | 20% |
| Monday | 83°F | Chance Showers And Thunderstorms | 10 mph W | 41% |
Forecast source: National Weather Service (api.weather.gov) for St. Marys (41.455, -78.520). Updated through the day.
Growing snapshot for St. Marys
Last spring frost
May 14
First fall frost
Oct 6
Growing season
143 days
Hardiness zone
5b
More local growing data for St. Marys: nearby ZIP 15857 weather · frost dates · planting calendar · Pennsylvania frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Glen Hazel 2 Ne Dam, Pa (8.4 mi from St. Marys). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.