Hornby, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.7 °C (low) to 13.4 °C (high). Annual precipitation averages 966.2 Millimeters. Hornby is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.2 °C | -0.8 °C | 58.17 mm |
| February | -8.7 °C | 0.6 °C | 46.99 mm |
| March | -5.4 °C | 5.2 °C | 70.87 mm |
| April | 0.4 °C | 13 °C | 82.04 mm |
| May | 6.7 °C | 19.8 °C | 83.82 mm |
| June | 12 °C | 24.1 °C | 106.17 mm |
| July | 14.2 °C | 26.4 °C | 96.52 mm |
| August | 13.4 °C | 25.6 °C | 99.31 mm |
| September | 9.8 °C | 21.9 °C | 100.58 mm |
| October | 4.8 °C | 15.1 °C | 90.68 mm |
| November | -0.2 °C | 7.9 °C | 68.58 mm |
| December | -5.3 °C | 2.1 °C | 62.48 mm |
| Annual | 2.7 °C | 13.4 °C | 966.21 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 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 |