Fishers Island, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 7.8 °C (low) to 14.6 °C (high). Annual precipitation averages 1188 Millimeters. Fishers Island is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.3 °C | 3.8 °C | 96.52 mm |
| February | -2.8 °C | 4.2 °C | 81.79 mm |
| March | 0.1 °C | 7.7 °C | 121.16 mm |
| April | 5.1 °C | 12.6 °C | 110.74 mm |
| May | 9.7 °C | 16.6 °C | 88.9 mm |
| June | 15.1 °C | 21.6 °C | 92.96 mm |
| July | 19.1 °C | 25.4 °C | 76.96 mm |
| August | 19 °C | 24.8 °C | 94.23 mm |
| September | 15.8 °C | 22.3 °C | 98.55 mm |
| October | 10.3 °C | 17.1 °C | 114.05 mm |
| November | 5 °C | 12 °C | 96.27 mm |
| December | 0.3 °C | 7.1 °C | 115.82 mm |
| Annual | 7.8 °C | 14.6 °C | 1187.95 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |