Hainesburg, New Jersey has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.6 °C (low) to 16.7 °C (high). Annual precipitation averages 1292.9 Millimeters. Hainesburg 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 | -7.1 °C | 2.9 °C | 91.44 mm |
| February | -6.3 °C | 4.7 °C | 73.66 mm |
| March | -2.6 °C | 9.3 °C | 100.33 mm |
| April | 3.2 °C | 16.6 °C | 102.87 mm |
| May | 8.9 °C | 22.1 °C | 106.68 mm |
| June | 14 °C | 26.6 °C | 124.46 mm |
| July | 16.8 °C | 29.2 °C | 119.13 mm |
| August | 15.8 °C | 28.2 °C | 121.41 mm |
| September | 11.8 °C | 24.7 °C | 126.75 mm |
| October | 5.4 °C | 18.1 °C | 125.73 mm |
| November | -0.3 °C | 11.7 °C | 89.66 mm |
| December | -3.9 °C | 6 °C | 110.74 mm |
| Annual | 4.6 °C | 16.7 °C | 1292.86 mm |
| 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 : -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 |