Deferiet, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2 °C (low) to 12.5 °C (high). Annual precipitation averages 1110.5 Millimeters. Deferiet is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.6 °C | -2.3 °C | 95.76 mm |
| February | -12 °C | -1.4 °C | 67.06 mm |
| March | -6.6 °C | 3.5 °C | 71.12 mm |
| April | 0.6 °C | 11.6 °C | 86.61 mm |
| May | 7.3 °C | 18.9 °C | 89.66 mm |
| June | 12.6 °C | 23.6 °C | 93.98 mm |
| July | 15.5 °C | 26.1 °C | 87.38 mm |
| August | 14.6 °C | 25.6 °C | 91.95 mm |
| September | 10.1 °C | 21.7 °C | 95.5 mm |
| October | 3.9 °C | 14.4 °C | 126.49 mm |
| November | -1.8 °C | 7.4 °C | 103.12 mm |
| December | -7.8 °C | 0.9 °C | 101.85 mm |
| Annual | 2 °C | 12.5 °C | 1110.48 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |