Annandale, New Jersey has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.2 °C (low) to 16.8 °C (high). Annual precipitation averages 1276.4 Millimeters. Annandale is located in USDA Plant Hardiness Zone 7a. 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 | -6.4 °C | 3.4 °C | 93.47 mm |
| February | -5.8 °C | 4.9 °C | 73.41 mm |
| March | -1.8 °C | 9.6 °C | 107.19 mm |
| April | 3.8 °C | 16.6 °C | 105.92 mm |
| May | 9.4 °C | 22 °C | 107.44 mm |
| June | 14.5 °C | 26.8 °C | 119.13 mm |
| July | 17.2 °C | 29.4 °C | 127.51 mm |
| August | 16.3 °C | 28.3 °C | 115.06 mm |
| September | 12.2 °C | 24.7 °C | 113.28 mm |
| October | 5.8 °C | 18.1 °C | 111 mm |
| November | 0.4 °C | 11.9 °C | 87.12 mm |
| December | -3.4 °C | 6.2 °C | 115.82 mm |
| Annual | 5.2 °C | 16.8 °C | 1276.35 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 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |