Flanders, New Jersey has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 41.5 °F (low) to 60.8 °F (high). Annual precipitation averages 52 Inches. Flanders 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 | 19.9 °F | 36.7 °F | 3.83 in. |
| February | 21.1 °F | 39.0 °F | 3.14 in. |
| March | 28.2 °F | 47.3 °F | 4.3 in. |
| April | 39.1 °F | 60.3 °F | 4.07 in. |
| May | 49.0 °F | 70.1 °F | 4.13 in. |
| June | 58.7 °F | 78.7 °F | 5.25 in. |
| July | 63.3 °F | 83.7 °F | 4.66 in. |
| August | 61.8 °F | 81.8 °F | 4.86 in. |
| September | 54.2 °F | 74.8 °F | 4.89 in. |
| October | 42.7 °F | 63.2 °F | 4.6 in. |
| November | 33.3 °F | 51.9 °F | 3.65 in. |
| December | 26.2 °F | 41.8 °F | 4.58 in. |
| Annual | 41.5 °F | 60.8 °F | 51.96 in. |
| 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 : -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 |