Mercersburg, PA Weather & Growing Conditions
This Afternoon
75°F
Partly Sunny
Partly sunny, with a high near 75. South wind around 10 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 75°F | Partly Sunny | 10 mph S | 1% |
| Tonight | 63°F | Rain Showers | 6 to 9 mph SE | 99% |
| Thursday | 76°F | Rain Showers Likely | 2 to 8 mph S | 74% |
| Thursday Night | 53°F | Mostly Cloudy then Patchy Fog | 2 mph W | 13% |
| Friday | 69°F | Patchy Fog then Partly Sunny | 0 to 5 mph W | 7% |
| Friday Night | 45°F | Partly Cloudy | 2 to 6 mph NW | 4% |
| Saturday | 57°F | Mostly Sunny then Slight Chance Rain Showers | 6 to 13 mph NW | 19% |
| Saturday Night | 42°F | Slight Chance Rain Showers then Partly Cloudy | 9 to 13 mph NW | 19% |
| Sunday | 60°F | Mostly Sunny | 8 to 13 mph NW | 2% |
| Sunday Night | 38°F | Mostly Clear | 8 mph W | 0% |
| Monday | 61°F | Sunny | 7 to 12 mph W | 0% |
| Monday Night | 38°F | Mostly Clear | 6 mph W | 0% |
| Tuesday | 66°F | Sunny | 3 to 9 mph W | 0% |
| Tuesday Night | 38°F | Mostly Clear | 5 mph W | 1% |
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 Nov 4, 2026.