Mercersburg, PA Weather & Growing Conditions
Today
85°F
Mostly Sunny
Mostly sunny, with a high near 85. East wind around 3 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 85°F | Mostly Sunny | 3 mph E | 0% |
| Tonight | 66°F | Mostly Cloudy then Slight Chance Rain Showers | 2 mph E | 19% |
| Wednesday | 84°F | Showers And Thunderstorms Likely | 3 mph E | 65% |
| Wednesday Night | 69°F | Chance Showers And Thunderstorms | 3 mph SE | 41% |
| Thursday | 88°F | Patchy Fog then Showers And Thunderstorms Likely | 1 to 5 mph S | 63% |
| Thursday Night | 69°F | Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms | 0 to 3 mph SW | 63% |
| Friday | 88°F | Partly Sunny then Showers And Thunderstorms Likely | 0 to 5 mph SW | 57% |
| Friday Night | 68°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 2 mph W | 57% |
| Saturday | 86°F | Partly Sunny then Chance Showers And Thunderstorms | 0 to 5 mph W | 46% |
| Saturday Night | 68°F | Chance Showers And Thunderstorms | 2 mph W | 46% |
| Sunday | 88°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 3 mph W | 16% |
| Sunday Night | 69°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 3 mph W | 16% |
| Monday | 90°F | Mostly Sunny | 1 to 7 mph W | 12% |
| Monday Night | 69°F | Partly Cloudy | 2 to 6 mph W | 13% |
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 Aug 4, 2026.