Castle Shannon, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Castle Shannon, a borough in Allegheny County, Pennsylvania.
Overnight
55°F
Mostly Clear
Mostly clear, with a low around 55. South wind around 5 mph.
7-day forecast for Castle Shannon
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 55°F | Mostly Clear | 5 mph S | 1% |
| Wednesday | 77°F | Partly Sunny then Slight Chance Light Rain | 5 to 12 mph S | 22% |
| Wednesday Night | 61°F | Light Rain | 10 to 14 mph S | 95% |
| Thursday | 69°F | Chance Light Rain then Mostly Sunny | 8 to 14 mph SW | 25% |
| Thursday Night | 49°F | Partly Cloudy | 7 mph SW | 1% |
| Friday | 62°F | Partly Sunny then Slight Chance Light Rain | 5 to 9 mph SW | 21% |
| Friday Night | 43°F | Chance Light Rain | 7 to 10 mph W | 30% |
| Saturday | 52°F | Chance Light Rain | 10 to 14 mph W | 29% |
| Saturday Night | 38°F | Slight Chance Light Rain | 8 to 12 mph W | 24% |
| Sunday | 54°F | Partly Sunny | 8 to 14 mph W | 7% |
| Sunday Night | 36°F | Partly Cloudy | 10 mph W | 5% |
| Monday | 55°F | Mostly Sunny | 9 to 14 mph W | 10% |
| Monday Night | 38°F | Mostly Clear | 7 to 12 mph SW | 8% |
| Tuesday | 59°F | Mostly Sunny | 12 to 16 mph SW | 3% |
Forecast source: National Weather Service (api.weather.gov) for Castle Shannon (40.366, -80.019). Updated through the day.
Growing snapshot for Castle Shannon
Last spring frost
Apr 18
First fall frost
Oct 28
Growing season
193 days
Hardiness zone
6b
More local growing data for Castle Shannon: nearby ZIP 15234 weather · frost dates · planting calendar · Pennsylvania frost dates
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Climate data from the nearest NOAA station, Pittsburgh Allegheny Co Ap, Pa (5.1 mi from Castle Shannon). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.