Princeton, 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 1244.1 Millimeters. Princeton is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.2 °C | 4.3 °C | 88.9 mm |
| February | -4.3 °C | 5.7 °C | 70.1 mm |
| March | -0.4 °C | 10.1 °C | 111 mm |
| April | 5.1 °C | 16.8 °C | 97.03 mm |
| May | 10.5 °C | 22.2 °C | 103.89 mm |
| June | 15.6 °C | 27.2 °C | 116.59 mm |
| July | 18.5 °C | 29.8 °C | 128.78 mm |
| August | 17.6 °C | 28.8 °C | 116.33 mm |
| September | 13.6 °C | 25.3 °C | 106.93 mm |
| October | 7.2 °C | 18.6 °C | 103.38 mm |
| November | 1.6 °C | 12.7 °C | 86.87 mm |
| December | -2.4 °C | 7 °C | 114.3 mm |
| Annual | 6.5 °C | 17.4 °C | 1244.1 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 |