Brass Castle, New Jersey has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.9 °C (low) to 16.2 °C (high). Annual precipitation averages 1317 Millimeters. Brass Castle is located in USDA Plant Hardiness Zone 7a. 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 | -6.8 °C | 2.8 °C | 93.22 mm |
| February | -6.2 °C | 4.4 °C | 76.71 mm |
| March | -2.3 °C | 8.9 °C | 99.06 mm |
| April | 3.7 °C | 15.9 °C | 101.85 mm |
| May | 9.2 °C | 21.4 °C | 107.95 mm |
| June | 14.2 °C | 26.2 °C | 127.25 mm |
| July | 16.9 °C | 28.8 °C | 126.49 mm |
| August | 16.1 °C | 27.7 °C | 125.73 mm |
| September | 12.1 °C | 24.1 °C | 134.37 mm |
| October | 5.8 °C | 17.7 °C | 121.16 mm |
| November | 0.2 °C | 11.3 °C | 90.93 mm |
| December | -3.8 °C | 5.6 °C | 112.27 mm |
| Annual | 4.9 °C | 16.2 °C | 1316.99 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 7a : -17.8°C to -15°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 |