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
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| 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.