New Philadelphia, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.1 °C (low) to 16.2 °C (high). Annual precipitation averages 1324.4 Millimeters. New Philadelphia is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.4 °C | 2.6 °C | 93.22 mm |
| February | -6.8 °C | 4.1 °C | 72.9 mm |
| March | -2.6 °C | 8.8 °C | 102.87 mm |
| April | 2.9 °C | 16 °C | 110.49 mm |
| May | 8.4 °C | 21.8 °C | 109.98 mm |
| June | 13.6 °C | 26.3 °C | 129.54 mm |
| July | 15.8 °C | 28.9 °C | 125.22 mm |
| August | 14.9 °C | 28 °C | 114.81 mm |
| September | 10.8 °C | 24.2 °C | 133.6 mm |
| October | 4.5 °C | 17.7 °C | 124.46 mm |
| November | -0.4 °C | 10.9 °C | 100.33 mm |
| December | -4.4 °C | 5.2 °C | 106.93 mm |
| Annual | 4.1 °C | 16.2 °C | 1324.35 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 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 | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |