Mertztown, PA Weather & Growing Conditions
Tonight
58°F
Mostly Cloudy then Rain Showers Likely
Rain showers likely after 1am. Mostly cloudy, with a low around 58. Southeast wind 5 to 10 mph. Chance of precipitation is 70%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 58°F | Mostly Cloudy then Rain Showers Likely | 5 to 10 mph SE | 67% |
| Sunday | 73°F | Rain Showers | 5 to 10 mph S | 94% |
| Sunday Night | 56°F | Showers And Thunderstorms then Mostly Cloudy | 5 to 10 mph NW | 81% |
| Monday | 68°F | Partly Sunny then Slight Chance Rain Showers | 5 to 10 mph NE | 23% |
| Monday Night | 50°F | Chance Rain Showers | 5 to 15 mph NE | 34% |
| Tuesday | 62°F | Chance Rain Showers | 10 to 15 mph NE | 41% |
| Tuesday Night | 49°F | Chance Rain Showers | 10 to 15 mph NE | 37% |
| Wednesday | 61°F | Slight Chance Rain Showers | 15 mph NE | 22% |
| Wednesday Night | 48°F | Slight Chance Rain Showers | 15 mph NE | 21% |
| Thursday | 61°F | Chance Rain Showers | 10 to 15 mph NE | 25% |
| Thursday Night | 48°F | Chance Rain Showers | 10 to 15 mph NE | 32% |
| Friday | 65°F | Chance Rain Showers | 10 to 15 mph N | 29% |
| Friday Night | 49°F | Chance Rain Showers | 10 to 15 mph N | 29% |
| Saturday | 68°F | Chance Rain Showers | 10 to 15 mph N | 28% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Mertztown, PA
Last spring frost
Apr 26
First fall frost
Oct 14
Growing season
171 days
Hardiness zone
6b
Explore more for Mertztown, PA: full frost dates · planting calendar · Pennsylvania frost dates
Climate data from the nearest NOAA station, Rodale Rsch Ctr, Pa (6.5 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.