Harman US

Mercersburg, PA Weather & Growing Conditions

This Afternoon
76°F
Mostly Cloudy
Mostly cloudy, with a high near 76. East wind around 3 mph.

7-day forecast

WhenTempForecastWindPrecip
This Afternoon 76°F Mostly Cloudy 3 mph E 10%
Tonight 64°F Chance Rain Showers 3 to 9 mph SE 41%
Sunday 78°F Chance Showers And Thunderstorms 3 to 9 mph S 86%
Sunday Night 58°F Showers And Thunderstorms 2 to 10 mph NW 86%
Monday 67°F Chance Rain Showers 6 to 10 mph NE 33%
Monday Night 53°F Rain Showers Likely 5 to 8 mph NE 61%
Tuesday 60°F Rain Showers Likely 8 mph NE 70%
Tuesday Night 50°F Rain Showers Likely 7 to 10 mph NE 61%
Wednesday 59°F Rain Showers Likely 10 mph NE 56%
Wednesday Night 51°F Chance Rain Showers 7 to 10 mph NE 45%
Thursday 61°F Chance Rain Showers 6 to 10 mph NE 45%
Thursday Night 50°F Chance Rain Showers 8 mph N 40%
Friday 67°F Slight Chance Rain Showers 8 mph N 23%
Friday Night 50°F Slight Chance Rain Showers 5 to 8 mph N 17%

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.