Northwood, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.7 °C (low) to 16 °C (high). Annual precipitation averages 1101.6 Millimeters. Northwood 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 | -6.8 °C | 2.2 °C | 76.2 mm |
| February | -6.2 °C | 3.8 °C | 65.53 mm |
| March | -2.5 °C | 8.7 °C | 87.63 mm |
| April | 3.3 °C | 16.2 °C | 96.52 mm |
| May | 8.9 °C | 21.8 °C | 104.65 mm |
| June | 14.1 °C | 26.3 °C | 106.17 mm |
| July | 16.4 °C | 28.7 °C | 99.31 mm |
| August | 15.6 °C | 27.9 °C | 98.81 mm |
| September | 11.6 °C | 24 °C | 109.98 mm |
| October | 5.3 °C | 17.3 °C | 96.27 mm |
| November | 0.1 °C | 10.6 °C | 76.96 mm |
| December | -3.8 °C | 4.5 °C | 83.57 mm |
| Annual | 4.7 °C | 16 °C | 1101.6 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 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |