Mercersburg, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Mercersburg, a borough in Franklin County, Pennsylvania.
Tonight
56°F
Partly Cloudy
Partly cloudy, with a low around 56. North wind around 6 mph.
7-day forecast for Mercersburg
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 56°F | Partly Cloudy | 6 mph N | 0% |
| Saturday | 76°F | Mostly Sunny | 6 mph E | 3% |
| Saturday Night | 65°F | Chance Rain Showers | 3 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 | 9 mph NE | 41% |
| Monday Night | 57°F | Rain Showers Likely | 8 mph NE | 66% |
| Tuesday | 62°F | Showers And Thunderstorms | 9 mph NE | 76% |
| Tuesday Night | 52°F | Showers And Thunderstorms | 9 mph NE | 76% |
| Wednesday | 59°F | Rain Showers Likely | 9 mph NE | 61% |
| Wednesday Night | 52°F | Showers And Thunderstorms Likely | 5 to 8 mph NE | 56% |
| Thursday | 62°F | Chance Showers And Thunderstorms | 8 mph NE | 51% |
| Thursday Night | 52°F | Chance Rain Showers | 5 mph N | 35% |
| Friday | 68°F | Chance Rain Showers | 7 mph N | 27% |
Forecast source: National Weather Service (api.weather.gov) for Mercersburg (39.832, -77.903). Updated through the day.
Growing snapshot for Mercersburg
Last spring frost
Apr 7
First fall frost
Nov 4
Growing season
209 days
Hardiness zone
7a
More local growing data for Mercersburg: nearby ZIP 17236 weather · frost dates · planting calendar · Pennsylvania frost dates
Nearby towns & communities
Blue Ridge Summit
Chambersburg
Fayetteville
Fort Loudon
Greencastle
Guilford
Marion
Mont Alto
Orrstown
Pen Mar
Rouzerville
Scotland
State Line
Wayne Heights
Waynesboro
Climate data from the nearest NOAA station, Hagerstown Washington Co Ap, Md (13.2 mi from Mercersburg). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.