Butler, New Jersey has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 5.5 °C (low) to 16.6 °C (high). Annual precipitation averages 1254.5 Millimeters. Butler 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 | 3.1 °C | 92.96 mm |
| February | -5.6 °C | 4.6 °C | 69.6 mm |
| March | -1.6 °C | 9.2 °C | 105.92 mm |
| April | 4.3 °C | 16 °C | 99.31 mm |
| May | 9.7 °C | 21.7 °C | 98.04 mm |
| June | 14.8 °C | 26.4 °C | 128.02 mm |
| July | 17.6 °C | 29.5 °C | 107.95 mm |
| August | 16.7 °C | 28.4 °C | 120.9 mm |
| September | 12.5 °C | 24.7 °C | 113.54 mm |
| October | 6.1 °C | 17.9 °C | 111.76 mm |
| November | 1 °C | 11.6 °C | 95.76 mm |
| December | -3.1 °C | 5.8 °C | 110.74 mm |
| Annual | 5.5 °C | 16.6 °C | 1254.5 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |