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Belfast, PA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Belfast, a community in Northampton County, Pennsylvania.

This Afternoon
72°F
Partly Sunny
Partly sunny, with a high near 72. Southeast wind around 0 mph.

7-day forecast for Belfast

WhenTempForecastWindPrecip
This Afternoon 72°F Partly Sunny 0 mph 1%
Tonight 57°F Mostly Cloudy then Rain Showers Likely 5 mph E 69%
Sunday 72°F Rain Showers 5 mph SE 97%
Sunday Night 56°F Showers And Thunderstorms then Mostly Cloudy 5 to 10 mph W 83%
Monday 69°F Partly Sunny then Slight Chance Rain Showers 5 to 10 mph NE 22%
Monday Night 50°F Chance Rain Showers 5 to 10 mph NE 32%
Tuesday 63°F Chance Rain Showers 10 mph NE 38%
Tuesday Night 48°F Chance Rain Showers then Mostly Cloudy 10 to 15 mph NE 33%
Wednesday 62°F Slight Chance Rain Showers 15 mph NE 20%
Wednesday Night 48°F Slight Chance Rain Showers 10 to 15 mph NE 21%
Thursday 61°F Slight Chance Rain Showers 10 to 15 mph NE 24%
Thursday Night 48°F Chance Rain Showers 10 to 15 mph NE 28%
Friday 65°F Chance Rain Showers 10 to 15 mph N 31%
Friday Night 49°F Chance Rain Showers 10 to 15 mph N 31%

Forecast source: National Weather Service (api.weather.gov) for Belfast (40.782, -75.274). Updated through the day.

Growing snapshot for Belfast

Last spring frost
Apr 18
First fall frost
Oct 25
Growing season
188 days
Hardiness zone
7a

More local growing data for Belfast: nearby ZIP 18083 weather · frost dates · planting calendar · Pennsylvania frost dates

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Climate data from the nearest NOAA station, Phillipsburg-Easton Brg, Nj (5.3 mi from Belfast). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.