Long Valley, New Jersey has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 5.1 °C (low) to 16.1 °C (high). Annual precipitation averages 1339.3 Millimeters. Long Valley is located in USDA Plant Hardiness Zone 6b. 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 | -6.8 °C | 2.8 °C | 99.82 mm |
| February | -6.1 °C | 4.3 °C | 79.5 mm |
| March | -2.1 °C | 8.9 °C | 106.17 mm |
| April | 3.8 °C | 16.1 °C | 104.9 mm |
| May | 9.4 °C | 21.3 °C | 105.16 mm |
| June | 14.4 °C | 25.9 °C | 129.79 mm |
| July | 17.2 °C | 28.5 °C | 121.16 mm |
| August | 16.3 °C | 27.6 °C | 131.06 mm |
| September | 12.2 °C | 23.8 °C | 126.75 mm |
| October | 5.8 °C | 17.4 °C | 125.22 mm |
| November | 0.3 °C | 11.3 °C | 93.73 mm |
| December | -3.5 °C | 5.6 °C | 116.08 mm |
| Annual | 5.1 °C | 16.1 °C | 1339.34 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 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |