New Castle Northwest, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for New Castle Northwest, a community in Lawrence County, Pennsylvania.
This Afternoon
79°F
Sunny
Sunny. High near 79, with temperatures falling to around 73 in the afternoon. South wind around 9 mph.
7-day forecast for New Castle Northwest
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 79°F | Sunny | 9 mph S | 1% |
| Tonight | 55°F | Mostly Clear | 5 mph SE | 3% |
| Wednesday | 76°F | Partly Sunny then Chance Light Rain | 5 to 10 mph S | 28% |
| Wednesday Night | 59°F | Light Rain | 6 to 9 mph S | 100% |
| Thursday | 69°F | Mostly Sunny | 5 to 10 mph SW | 13% |
| Thursday Night | 45°F | Partly Cloudy | 0 to 3 mph W | 2% |
| Friday | 64°F | Partly Sunny | 0 to 6 mph NW | 14% |
| Friday Night | 42°F | Chance Light Rain | 3 mph NW | 28% |
| Saturday | 55°F | Chance Light Rain | 3 to 9 mph W | 31% |
| Saturday Night | 34°F | Chance Light Rain then Mostly Cloudy | 2 to 6 mph W | 31% |
| Sunday | 56°F | Partly Sunny then Slight Chance Light Rain | 2 to 8 mph W | 18% |
| Sunday Night | 32°F | Slight Chance Light Rain | 6 mph W | 19% |
| Monday | 57°F | Chance Light Rain | 6 to 10 mph W | 29% |
| Monday Night | 34°F | Chance Light Rain then Partly Cloudy | 7 mph SW | 29% |
Forecast source: National Weather Service (api.weather.gov) for New Castle Northwest (41.022, -80.356). Updated through the day.
Growing snapshot for New Castle Northwest
Last spring frost
Apr 30
First fall frost
Oct 23
Growing season
175 days
Hardiness zone
6a
More local growing data for New Castle Northwest: nearby ZIP 16105 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 Galilee
New Wilmington
Oakland
Oakwood
Pulaski
S.N.P.J.
South New Castle
Volant
Wampum
West Pittsburg
Wurtemburg
Climate data from the nearest NOAA station, New Castle 1 N, Pa (2.8 mi from New Castle Northwest). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.