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
75°F
Chance Light Rain
A chance of rain after 1pm. Mostly cloudy. High near 75, with temperatures falling to around 68 in the afternoon. South wind around 9 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for New Castle Northwest
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 75°F | Chance Light Rain | 9 mph S | 44% |
| Tonight | 58°F | Light Rain Likely | 6 to 9 mph S | 73% |
| Thursday | 68°F | Slight Chance Light Rain then Mostly Sunny | 5 to 12 mph SW | 18% |
| Thursday Night | 45°F | Mostly Cloudy | 1 to 5 mph SW | 5% |
| Friday | 60°F | Chance Light Rain | 2 to 7 mph W | 53% |
| Friday Night | 36°F | Chance Light Rain | 5 mph W | 53% |
| Saturday | 53°F | Chance Light Rain | 5 to 12 mph W | 47% |
| Saturday Night | 32°F | Chance Light Rain then Mostly Cloudy | 3 to 8 mph W | 47% |
| Sunday | 56°F | Mostly Sunny | 5 to 10 mph W | 3% |
| Sunday Night | 31°F | Partly Cloudy | 6 mph W | 6% |
| Monday | 59°F | Mostly Sunny | 3 to 10 mph W | 6% |
| Monday Night | 33°F | Mostly Clear | 5 mph SW | 3% |
| Tuesday | 63°F | Sunny | 5 to 9 mph SW | 2% |
| Tuesday Night | 32°F | Partly Cloudy | 1 to 5 mph W | 2% |
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 4, 2026.