Northumberland, PA Weather & Growing Conditions
Today
74°F
Mostly Sunny
Mostly sunny, with a high near 74. South wind 3 to 8 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 74°F | Mostly Sunny | 3 to 8 mph S | 1% |
| Tonight | 59°F | Mostly Cloudy then Light Rain | 7 to 10 mph S | 78% |
| Thursday | 72°F | Light Rain | 5 to 12 mph S | 91% |
| Thursday Night | 52°F | Chance Light Rain then Mostly Cloudy | 0 to 3 mph W | 34% |
| Friday | 67°F | Slight Chance Light Rain | 1 mph NW | 16% |
| Friday Night | 46°F | Partly Cloudy | 2 mph NW | 13% |
| Saturday | 59°F | Slight Chance Light Rain | 3 to 8 mph W | 24% |
| Saturday Night | 41°F | Slight Chance Light Rain | 7 mph W | 24% |
| Sunday | 58°F | Mostly Sunny | 5 to 8 mph W | 5% |
| Sunday Night | 38°F | Partly Cloudy | 6 mph W | 6% |
| Monday | 58°F | Mostly Sunny | 5 to 10 mph W | 9% |
| Monday Night | 36°F | Partly Cloudy | 6 mph SW | 9% |
| Tuesday | 62°F | Mostly Sunny | 3 to 9 mph SW | 3% |
| Tuesday Night | 36°F | Partly Cloudy | 6 mph W | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Northumberland, PA
Last spring frost
Apr 30
First fall frost
Oct 13
Growing season
166 days
Hardiness zone
6b
Explore more for Northumberland, PA: full frost dates · planting calendar · Pennsylvania frost dates
Climate data from the nearest NOAA station, Sunbury, Pa (5.5 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.