St. Clair, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Clair, a borough in Schuylkill County, Pennsylvania.
This Afternoon
78°F
Mostly Sunny
Mostly sunny, with a high near 78. North wind around 5 mph.
7-day forecast for St. Clair
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 78°F | Mostly Sunny | 5 mph N | 0% |
| Tonight | 50°F | Mostly Clear then Areas Of Fog | 1 to 5 mph N | 0% |
| Saturday | 71°F | Areas Of Fog then Mostly Sunny | 2 mph E | 2% |
| Saturday Night | 57°F | Mostly Cloudy then Rain Showers Likely | 1 to 5 mph SE | 68% |
| Sunday | 70°F | Rain Showers | 6 mph S | 98% |
| Sunday Night | 57°F | Showers And Thunderstorms | 5 mph NW | 98% |
| Monday | 68°F | Chance Rain Showers | 5 mph NE | 32% |
| Monday Night | 52°F | Chance Rain Showers | 3 to 7 mph E | 40% |
| Tuesday | 61°F | Chance Rain Showers | 7 mph E | 45% |
| Tuesday Night | 49°F | Chance Rain Showers | 8 mph E | 45% |
| Wednesday | 60°F | Chance Rain Showers | 8 mph E | 41% |
| Wednesday Night | 49°F | Chance Showers And Thunderstorms | 7 mph E | 39% |
| Thursday | 62°F | Chance Showers And Thunderstorms | 7 mph NE | 39% |
| Thursday Night | 50°F | Chance Showers And Thunderstorms | 3 mph NE | 38% |
Forecast source: National Weather Service (api.weather.gov) for St. Clair (40.721, -76.190). Updated through the day.
Growing snapshot for St. Clair
Last spring frost
Apr 30
First fall frost
Oct 22
Growing season
175 days
Hardiness zone
6b
More local growing data for St. Clair: nearby ZIP 17970 weather · frost dates · planting calendar · Pennsylvania frost dates
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Climate data from the nearest NOAA station, Mahanoy City 2 N, Pa (8.2 mi from St. Clair). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 18, 2026.