Harman US

Mercersburg, PA Weather & Growing Conditions

Overnight
56°F
Partly Cloudy
Partly cloudy, with a low around 56. Northeast wind around 6 mph.

7-day forecast

WhenTempForecastWindPrecip
Overnight 56°F Partly Cloudy 6 mph NE 0%
Saturday 77°F Partly Sunny 6 mph E 3%
Saturday Night 65°F Chance Rain Showers 2 to 9 mph SE 37%
Sunday 80°F Showers And Thunderstorms 3 to 9 mph S 87%
Sunday Night 61°F Showers And Thunderstorms 1 to 9 mph NW 87%
Monday 70°F Chance Rain Showers 6 to 9 mph NE 42%
Monday Night 57°F Rain Showers Likely 6 to 9 mph NE 67%
Tuesday 62°F Showers And Thunderstorms 9 mph NE 76%
Tuesday Night 52°F Showers And Thunderstorms 7 to 10 mph NE 76%
Wednesday 59°F Rain Showers Likely 7 to 10 mph NE 62%
Wednesday Night 52°F Showers And Thunderstorms Likely 6 to 9 mph NE 57%
Thursday 62°F Chance Showers And Thunderstorms 6 to 9 mph NE 51%
Thursday Night 52°F Chance Rain Showers 6 mph N 34%
Friday 68°F Chance Rain Showers 6 mph N 27%

Forecast source: National Weather Service (api.weather.gov). Updated through the day.

Growing snapshot for Mercersburg, PA

Last spring frost
Apr 7
First fall frost
Nov 4
Growing season
209 days
Hardiness zone
7a

Explore more for Mercersburg, PA: full frost dates · planting calendar · Pennsylvania frost dates

Climate data from the nearest NOAA station, Hagerstown Washington Co Ap, Md (13.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.