Castle Shannon, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Castle Shannon, a borough in Allegheny County, Pennsylvania.
This Afternoon
74°F
Partly Sunny
Partly sunny, with a high near 74. Southeast wind around 5 mph.
7-day forecast for Castle Shannon
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 74°F | Partly Sunny | 5 mph SE | 14% |
| Tonight | 66°F | Showers And Thunderstorms | 5 to 8 mph S | 76% |
| Sunday | 77°F | Showers And Thunderstorms | 8 to 12 mph SW | 97% |
| Sunday Night | 57°F | Chance Showers And Thunderstorms | 8 to 12 mph N | 48% |
| Monday | 69°F | Chance Rain Showers | 13 mph NE | 39% |
| Monday Night | 57°F | Rain Showers Likely | 13 mph NE | 62% |
| Tuesday | 66°F | Rain Showers Likely | 15 mph E | 66% |
| Tuesday Night | 55°F | Rain Showers | 16 mph E | 75% |
| Wednesday | 63°F | Rain Showers Likely | 16 mph E | 73% |
| Wednesday Night | 53°F | Rain Showers Likely | 12 to 16 mph E | 55% |
| Thursday | 65°F | Rain Showers Likely | 13 mph E | 55% |
| Thursday Night | 51°F | Slight Chance Rain Showers | 7 to 10 mph NE | 16% |
| Friday | 68°F | Slight Chance Rain Showers | 9 mph NE | 15% |
| Friday Night | 51°F | Partly Cloudy | 6 to 9 mph N | 12% |
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 Sep 19, 2026.