Mercersburg, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Mercersburg, a borough in Franklin County, Pennsylvania.
Overnight
60°F
Mostly Clear
Mostly clear, with a low around 60. North wind around 2 mph.
7-day forecast for Mercersburg
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 60°F | Mostly Clear | 2 mph N | 0% |
| Tuesday | 85°F | Mostly Sunny | 3 mph NE | 0% |
| Tuesday Night | 66°F | Mostly Cloudy then Slight Chance Rain Showers | 2 mph E | 18% |
| Wednesday | 84°F | Showers And Thunderstorms Likely | 0 to 5 mph E | 64% |
| Wednesday Night | 69°F | Chance Showers And Thunderstorms | 0 to 3 mph SE | 42% |
| Thursday | 88°F | Patchy Fog then Showers And Thunderstorms Likely | 1 to 5 mph S | 64% |
| Thursday Night | 70°F | Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms | 0 to 3 mph SW | 64% |
| Friday | 88°F | Partly Sunny then Showers And Thunderstorms Likely | 0 to 5 mph W | 57% |
| Friday Night | 68°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 0 to 3 mph SW | 57% |
| Saturday | 87°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 | 89°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 0 to 5 mph W | 15% |
| Sunday Night | 69°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 0 to 3 mph W | 15% |
| Monday | 90°F | Mostly Sunny | 0 to 7 mph W | 13% |
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 Aug 4, 2026.