Mertztown, PA Weather & Growing Conditions
Tonight
59°F
Mostly Cloudy then Slight Chance Light Rain
A slight chance of rain after 5am. Mostly cloudy, with a low around 59. South wind 5 to 10 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 59°F | Mostly Cloudy then Slight Chance Light Rain | 5 to 10 mph S | 18% |
| Thursday | 69°F | Light Rain | 5 to 10 mph S | 90% |
| Thursday Night | 58°F | Light Rain Likely | 0 to 5 mph SW | 55% |
| Friday | 67°F | Slight Chance Light Rain | 0 to 5 mph W | 23% |
| Friday Night | 48°F | Slight Chance Light Rain then Partly Cloudy | 0 to 5 mph NW | 20% |
| Saturday | 61°F | Mostly Sunny | 5 to 10 mph W | 14% |
| Saturday Night | 43°F | Partly Cloudy then Slight Chance Light Rain | 10 to 15 mph NW | 15% |
| Sunday | 58°F | Slight Chance Light Rain then Mostly Sunny | 10 to 15 mph W | 15% |
| Sunday Night | 39°F | Mostly Clear | 10 mph W | 0% |
| Monday | 58°F | Sunny | 10 to 15 mph W | 1% |
| Monday Night | 38°F | Mostly Clear | 5 to 10 mph W | 0% |
| Tuesday | 62°F | Sunny | 5 to 15 mph W | 1% |
| Tuesday Night | 38°F | Mostly Clear | 5 to 10 mph W | 1% |
| Veterans Day | 59°F | Sunny | 5 to 10 mph NW | 1% |
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 Nov 5, 2026.