Brentwood, New York has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7.4 °C (low) to 16.5 °C (high). Annual precipitation averages 1259.3 Millimeters. Brentwood is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.1 °C | 4.2 °C | 98.55 mm |
| February | -3.4 °C | 5.3 °C | 87.38 mm |
| March | 0.1 °C | 9.1 °C | 123.19 mm |
| April | 5.1 °C | 15.4 °C | 109.47 mm |
| May | 10.5 °C | 20.8 °C | 95.5 mm |
| June | 16.1 °C | 25.7 °C | 106.93 mm |
| July | 19.4 °C | 28.7 °C | 86.36 mm |
| August | 18.8 °C | 27.6 °C | 106.68 mm |
| September | 15.1 °C | 24 °C | 101.6 mm |
| October | 8.9 °C | 17.7 °C | 123.95 mm |
| November | 3.4 °C | 12.1 °C | 94.74 mm |
| December | -0.8 °C | 7.2 °C | 124.97 mm |
| Annual | 7.4 °C | 16.5 °C | 1259.32 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |