Fort Plain, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.7 °C (low) to 14.9 °C (high). Annual precipitation averages 997.2 Millimeters. Fort Plain 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 | -9.3 °C | -0.1 °C | 68.33 mm |
| February | -8.6 °C | 1.5 °C | 62.23 mm |
| March | -4.3 °C | 6.2 °C | 80.01 mm |
| April | 2.2 °C | 14.4 °C | 85.09 mm |
| May | 8.4 °C | 21.6 °C | 85.6 mm |
| June | 13.3 °C | 26.1 °C | 100.84 mm |
| July | 16.2 °C | 28.6 °C | 99.57 mm |
| August | 15.2 °C | 27.8 °C | 97.79 mm |
| September | 11.3 °C | 23.8 °C | 77.98 mm |
| October | 5.3 °C | 16.8 °C | 90.68 mm |
| November | -0.5 °C | 9.1 °C | 72.39 mm |
| December | -5.4 °C | 2.8 °C | 76.71 mm |
| Annual | 3.7 °C | 14.9 °C | 997.22 mm |
| 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 : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |