Castle Shannon, PA Weather & Growing Conditions
This Afternoon
79°F
Slight Chance Light Rain
A slight chance of rain. Mostly cloudy, with a high near 79. South wind around 12 mph. Chance of precipitation is 20%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 79°F | Slight Chance Light Rain | 12 mph S | 15% |
| Tonight | 61°F | Light Rain Likely | 13 mph SW | 72% |
| Thursday | 69°F | Chance Light Rain then Partly Sunny | 9 to 15 mph SW | 25% |
| Thursday Night | 49°F | Partly Cloudy | 8 mph SW | 0% |
| Friday | 62°F | Slight Chance Light Rain | 6 to 12 mph W | 23% |
| Friday Night | 42°F | Slight Chance Light Rain | 7 to 10 mph W | 23% |
| Saturday | 52°F | Mostly Cloudy then Slight Chance Light Rain | 10 to 15 mph W | 24% |
| Saturday Night | 38°F | Slight Chance Light Rain then Mostly Cloudy | 12 mph W | 24% |
| Sunday | 55°F | Partly Sunny | 9 to 15 mph W | 2% |
| Sunday Night | 37°F | Mostly Clear | 12 mph W | 1% |
| Monday | 57°F | Mostly Sunny | 10 to 16 mph W | 1% |
| Monday Night | 39°F | Mostly Clear | 8 to 12 mph SW | 1% |
| Tuesday | 61°F | Sunny | 12 to 15 mph SW | 0% |
| Tuesday Night | 38°F | Mostly Clear | 5 to 9 mph W | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Castle Shannon, PA
Last spring frost
Apr 18
First fall frost
Oct 28
Growing season
193 days
Hardiness zone
6b
Explore more for Castle Shannon, PA: full frost dates · planting calendar · Pennsylvania frost dates
Climate data from the nearest NOAA station, Pittsburgh Allegheny Co Ap, Pa (5.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.