Nassau, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.5 °C (low) to 14.8 °C (high). Annual precipitation averages 1096 Millimeters. Nassau is located in USDA Plant Hardiness Zone 6a. 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 | -9.3 °C | 0.3 °C | 70.87 mm |
| February | -8.6 °C | 1.9 °C | 57.66 mm |
| March | -3.9 °C | 6.8 °C | 75.18 mm |
| April | 2.2 °C | 14.6 °C | 85.34 mm |
| May | 8.2 °C | 21.2 °C | 91.95 mm |
| June | 13.3 °C | 25.6 °C | 115.82 mm |
| July | 15.9 °C | 28.2 °C | 110.74 mm |
| August | 15.1 °C | 27.2 °C | 108.71 mm |
| September | 10.7 °C | 23.2 °C | 106.68 mm |
| October | 4.7 °C | 16.2 °C | 109.47 mm |
| November | -0.5 °C | 9.4 °C | 76.96 mm |
| December | -5.4 °C | 3.2 °C | 86.61 mm |
| Annual | 3.5 °C | 14.8 °C | 1095.99 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 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |