Port Leyden, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.5 °C (low) to 12.5 °C (high). Annual precipitation averages 1195.8 Millimeters. Port Leyden 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 | -12.5 °C | -2.4 °C | 102.62 mm |
| February | -11.8 °C | -1 °C | 77.47 mm |
| March | -7.1 °C | 3.6 °C | 77.72 mm |
| April | 0.1 °C | 11.6 °C | 91.19 mm |
| May | 6.5 °C | 19.3 °C | 99.06 mm |
| June | 11.7 °C | 23.6 °C | 105.41 mm |
| July | 14.3 °C | 26.1 °C | 105.66 mm |
| August | 13.4 °C | 25.5 °C | 103.38 mm |
| September | 9.2 °C | 21.4 °C | 101.35 mm |
| October | 3.6 °C | 14.1 °C | 125.73 mm |
| November | -1.9 °C | 7.1 °C | 100.33 mm |
| December | -7.7 °C | 0.8 °C | 105.92 mm |
| Annual | 1.5 °C | 12.5 °C | 1195.84 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 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 |