Trenton, New Jersey has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.2 °C (low) to 17.9 °C (high). Annual precipitation averages 1214.4 Millimeters. Trenton 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 | -4.4 °C | 4.8 °C | 90.17 mm |
| February | -3.6 °C | 6.3 °C | 70.1 mm |
| March | 0.3 °C | 10.6 °C | 110.49 mm |
| April | 5.8 °C | 17.3 °C | 90.93 mm |
| May | 11.2 °C | 22.6 °C | 101.6 mm |
| June | 16.4 °C | 27.7 °C | 112.78 mm |
| July | 19.4 °C | 30.2 °C | 127.25 mm |
| August | 18.4 °C | 29.3 °C | 113.54 mm |
| September | 14.5 °C | 25.8 °C | 101.35 mm |
| October | 8 °C | 19.1 °C | 100.33 mm |
| November | 2.4 °C | 13.2 °C | 85.09 mm |
| December | -1.7 °C | 7.6 °C | 110.74 mm |
| Annual | 7.2 °C | 17.9 °C | 1214.37 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 | Cfa - Humid Subtropical Climate |