Dunnstown, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4 °C (low) to 16.1 °C (high). Annual precipitation averages 1088.9 Millimeters. Dunnstown is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.7 °C | 1.7 °C | 73.66 mm |
| February | -7.1 °C | 3.6 °C | 59.44 mm |
| March | -3.1 °C | 8.7 °C | 82.3 mm |
| April | 2.6 °C | 16.4 °C | 90.17 mm |
| May | 8.3 °C | 22.5 °C | 99.31 mm |
| June | 13.4 °C | 26.7 °C | 99.06 mm |
| July | 15.8 °C | 29.2 °C | 114.81 mm |
| August | 14.9 °C | 28.1 °C | 112.01 mm |
| September | 10.9 °C | 24.1 °C | 113.79 mm |
| October | 4.7 °C | 17.4 °C | 89.92 mm |
| November | -0.6 °C | 10.3 °C | 76.45 mm |
| December | -4.4 °C | 4.1 °C | 77.98 mm |
| Annual | 4 °C | 16.1 °C | 1088.9 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |