St. Clair, PA Weather & Growing Conditions
Overnight
50°F
Patchy Fog
Patchy fog between 4am and 5am. Partly cloudy, with a low around 50. Northeast wind around 2 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 50°F | Patchy Fog | 2 mph NE | 0% |
| Saturday | 71°F | Partly Sunny | 3 mph E | 1% |
| Saturday Night | 55°F | Rain Showers | 1 to 5 mph SE | 79% |
| Sunday | 69°F | Rain Showers | 6 mph S | 97% |
| Sunday Night | 52°F | Showers And Thunderstorms | 2 to 6 mph W | 95% |
| Monday | 69°F | Mostly Cloudy | 6 mph NE | 6% |
| Monday Night | 47°F | Chance Rain Showers | 2 to 6 mph NE | 37% |
| Tuesday | 60°F | Chance Rain Showers | 6 mph E | 38% |
| Tuesday Night | 46°F | Chance Rain Showers | 5 to 8 mph E | 34% |
| Wednesday | 61°F | Chance Rain Showers | 9 mph E | 34% |
| Wednesday Night | 46°F | Chance Rain Showers | 8 mph E | 34% |
| Thursday | 61°F | Chance Rain Showers | 8 mph NE | 34% |
| Thursday Night | 46°F | Chance Rain Showers | 5 mph NE | 31% |
| Friday | 66°F | Slight Chance Rain Showers | 6 mph N | 23% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for St. Clair, PA
Last spring frost
Apr 30
First fall frost
Oct 22
Growing season
175 days
Hardiness zone
6b
Explore more for St. Clair, PA: full frost dates · planting calendar · Pennsylvania frost dates
Climate data from the nearest NOAA station, Mahanoy City 2 N, Pa (8.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.