Cortland, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.6 °C (low) to 13.4 °C (high). Annual precipitation averages 1073.7 Millimeters. Cortland is located in USDA Plant Hardiness Zone 5b. 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 | -9.8 °C | -0.5 °C | 75.44 mm |
| February | -9.3 °C | 0.7 °C | 65.28 mm |
| March | -5.5 °C | 4.9 °C | 84.33 mm |
| April | 0.9 °C | 12.4 °C | 89.41 mm |
| May | 7.1 °C | 19.5 °C | 84.84 mm |
| June | 12.2 °C | 24.1 °C | 108.71 mm |
| July | 14.6 °C | 26.6 °C | 105.16 mm |
| August | 13.8 °C | 25.8 °C | 90.42 mm |
| September | 9.7 °C | 22.1 °C | 101.09 mm |
| October | 4 °C | 14.9 °C | 96.77 mm |
| November | -0.8 °C | 8.2 °C | 81.28 mm |
| December | -5.8 °C | 2.3 °C | 90.93 mm |
| Annual | 2.6 °C | 13.4 °C | 1073.66 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 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 |