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St. Clair, PA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for St. Clair, a community in Blair County, Pennsylvania.

Overnight
52°F
Patchy Fog
Patchy fog. Partly cloudy, with a low around 52. North wind around 2 mph.

7-day forecast for St. Clair

WhenTempForecastWindPrecip
Overnight 52°F Patchy Fog 2 mph N 0%
Saturday 75°F Patchy Fog then Partly Sunny 1 to 5 mph E 3%
Saturday Night 62°F Chance Rain Showers 6 mph SE 53%
Sunday 77°F Showers And Thunderstorms 6 mph SW 96%
Sunday Night 55°F Showers And Thunderstorms 2 to 7 mph N 96%
Monday 68°F Chance Rain Showers 7 mph NE 34%
Monday Night 53°F Rain Showers Likely 7 mph E 66%
Tuesday 62°F Showers And Thunderstorms Likely 7 mph E 72%
Tuesday Night 48°F Rain Showers Likely 8 mph E 65%
Wednesday 59°F Rain Showers Likely 8 mph E 60%
Wednesday Night 49°F Showers And Thunderstorms Likely 6 mph E 56%
Thursday 62°F Chance Showers And Thunderstorms 5 mph NE 51%
Thursday Night 49°F Chance Rain Showers 3 mph NE 35%
Friday 69°F Slight Chance Rain Showers then Partly Sunny 1 to 5 mph N 22%

Forecast source: National Weather Service (api.weather.gov) for St. Clair (40.478, -78.228). Updated through the day.

Growing snapshot for St. Clair

Last spring frost
Apr 19
First fall frost
Oct 28
Growing season
191 days
Hardiness zone
6b

More local growing data for St. Clair: nearby ZIP 16693 weather · frost dates · planting calendar · Pennsylvania frost dates

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Climate data from the nearest NOAA station, Raystown Lake 2, Pa (9.8 mi from St. Clair). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.