Nelliston, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.7 °F (low) to 58.6 °F (high). Annual precipitation averages 39.2 Inches. Nelliston is located in USDA Plant Hardiness Zone 5b. 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 | 15.2 °F | 31.7 °F | 2.7 in. |
| February | 16.5 °F | 34.5 °F | 2.45 in. |
| March | 24.4 °F | 43.1 °F | 3.13 in. |
| April | 36.1 °F | 57.9 °F | 3.35 in. |
| May | 47.2 °F | 70.6 °F | 3.36 in. |
| June | 56.1 °F | 78.8 °F | 3.96 in. |
| July | 61.3 °F | 83.3 °F | 3.89 in. |
| August | 59.5 °F | 81.8 °F | 3.85 in. |
| September | 52.5 °F | 74.6 °F | 3.07 in. |
| October | 41.6 °F | 62.0 °F | 3.57 in. |
| November | 31.1 °F | 48.2 °F | 2.85 in. |
| December | 22.3 °F | 36.9 °F | 3.02 in. |
| Annual | 38.7 °F | 58.6 °F | 39.2 in. |
| 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 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |