Pennington, New Jersey has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.5 °C (low) to 17.4 °C (high). Annual precipitation averages 1238.3 Millimeters. Pennington is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.1 °C | 4.2 °C | 90.68 mm |
| February | -4.4 °C | 5.7 °C | 72.14 mm |
| March | -0.4 °C | 10.2 °C | 107.44 mm |
| April | 5.1 °C | 16.8 °C | 95.25 mm |
| May | 10.7 °C | 22.2 °C | 105.66 mm |
| June | 15.7 °C | 27.2 °C | 115.32 mm |
| July | 18.6 °C | 29.9 °C | 128.02 mm |
| August | 17.7 °C | 28.8 °C | 114.81 mm |
| September | 13.7 °C | 25.3 °C | 104.9 mm |
| October | 7.2 °C | 18.6 °C | 103.63 mm |
| November | 1.6 °C | 12.7 °C | 87.38 mm |
| December | -2.4 °C | 7 °C | 113.03 mm |
| Annual | 6.5 °C | 17.4 °C | 1238.26 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |