Mount Hermon, New Jersey has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 40.1 °F (low) to 61.4 °F (high). Annual precipitation averages 49.8 Inches. Mount Hermon is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.9 °F | 36.9 °F | 3.51 in. |
| February | 20.3 °F | 40.0 °F | 2.85 in. |
| March | 27.2 °F | 48.2 °F | 3.94 in. |
| April | 37.7 °F | 61.1 °F | 3.87 in. |
| May | 47.9 °F | 71.1 °F | 4.12 in. |
| June | 57.3 °F | 79.3 °F | 4.89 in. |
| July | 61.8 °F | 84.0 °F | 4.68 in. |
| August | 60.1 °F | 82.1 °F | 4.8 in. |
| September | 52.8 °F | 75.6 °F | 4.84 in. |
| October | 41.3 °F | 64.0 °F | 4.72 in. |
| November | 31.2 °F | 52.4 °F | 3.39 in. |
| December | 24.3 °F | 42.1 °F | 4.23 in. |
| Annual | 40.1 °F | 61.4 °F | 49.84 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |