South New Castle, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for South New Castle, a borough in Lawrence County, Pennsylvania.
Today
77°F
Slight Chance Rain Showers then Mostly Cloudy
A slight chance of rain showers before 11am. Mostly cloudy, with a high near 77. East wind around 5 mph. Chance of precipitation is 20%.
7-day forecast for South New Castle
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 77°F | Slight Chance Rain Showers then Mostly Cloudy | 5 mph E | 17% |
| Tonight | 62°F | Showers And Thunderstorms | 5 mph SE | 80% |
| Sunday | 76°F | Showers And Thunderstorms | 5 to 8 mph SW | 92% |
| Sunday Night | 52°F | Chance Rain Showers then Mostly Cloudy | 6 to 9 mph N | 39% |
| Monday | 68°F | Mostly Cloudy then Chance Rain Showers | 9 mph NE | 26% |
| Monday Night | 51°F | Chance Rain Showers | 7 to 10 mph NE | 53% |
| Tuesday | 63°F | Chance Rain Showers | 14 mph E | 53% |
| Tuesday Night | 49°F | Rain Showers Likely | 15 mph E | 57% |
| Wednesday | 63°F | Rain Showers Likely | 15 mph E | 57% |
| Wednesday Night | 50°F | Showers And Thunderstorms Likely | 9 to 13 mph E | 64% |
| Thursday | 66°F | Rain Showers Likely | 10 mph E | 59% |
| Thursday Night | 49°F | Slight Chance Rain Showers | 3 to 7 mph E | 21% |
| Friday | 69°F | Slight Chance Rain Showers | 7 mph NE | 16% |
| Friday Night | 48°F | Slight Chance Rain Showers then Partly Cloudy | 2 to 6 mph NE | 15% |
Forecast source: National Weather Service (api.weather.gov) for South New Castle (40.975, -80.346). Updated through the day.
Growing snapshot for South New Castle
Last spring frost
Apr 30
First fall frost
Oct 23
Growing season
175 days
Hardiness zone
6b
More local growing data for South New Castle: nearby ZIP 16160 weather · frost dates · planting calendar · Pennsylvania frost dates
Nearby towns & communities
Bessemer
Chewton
Edinburg
Ellport
Ellwood City
Enon Valley
Frisco
Frizzleburg
Hillsville
Mount Jackson
New Beaver
New Bedford
New Castle
New Castle Northwest
New Galilee
New Wilmington
Oakland
Oakwood
Pulaski
S.N.P.J.
Volant
Wampum
West Pittsburg
Wurtemburg
Climate data from the nearest NOAA station, New Castle 1 N, Pa (6.1 mi from South New Castle). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.