Mertztown, PA Weather & Growing Conditions
This Afternoon
69°F
Mostly Sunny
Mostly sunny, with a high near 69. South wind around 5 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 69°F | Mostly Sunny | 5 mph S | 1% |
| Tonight | 49°F | Partly Cloudy then Patchy Fog | 0 to 5 mph S | 2% |
| Wednesday | 74°F | Patchy Fog then Sunny | 0 to 10 mph SW | 6% |
| Wednesday Night | 58°F | Mostly Cloudy then Slight Chance Light Rain | 5 mph S | 18% |
| Thursday | 72°F | Light Rain Likely | 5 to 10 mph S | 74% |
| Thursday Night | 60°F | Light Rain Likely | 0 to 5 mph SW | 64% |
| Friday | 69°F | Light Rain Likely | 0 to 5 mph NW | 64% |
| Friday Night | 49°F | Light Rain Likely | 0 to 5 mph NW | 56% |
| Saturday | 64°F | Slight Chance Light Rain | 5 to 10 mph NW | 20% |
| Saturday Night | 40°F | Slight Chance Light Rain then Partly Cloudy | 5 to 10 mph NW | 17% |
| Sunday | 60°F | Mostly Sunny | 5 to 10 mph W | 12% |
| Sunday Night | 38°F | Partly Cloudy then Slight Chance Light Rain | 5 mph W | 20% |
| Monday | 59°F | Slight Chance Light Rain | 5 to 15 mph NW | 24% |
| Monday Night | 37°F | Slight Chance Light Rain | 5 to 10 mph W | 23% |
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 (4.3 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.