Allegany, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.7 °C (low) to 13.8 °C (high). Annual precipitation averages 1048 Millimeters. Allegany is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.9 °C | -0.2 °C | 72.39 mm |
| February | -9.7 °C | 1.2 °C | 52.58 mm |
| March | -6.1 °C | 6.1 °C | 69.34 mm |
| April | -0.2 °C | 13.4 °C | 86.36 mm |
| May | 6 °C | 20.3 °C | 93.73 mm |
| June | 10.8 °C | 24.5 °C | 113.54 mm |
| July | 13.2 °C | 26.6 °C | 110.49 mm |
| August | 12.7 °C | 25.7 °C | 103.63 mm |
| September | 8.9 °C | 22.2 °C | 99.06 mm |
| October | 2.9 °C | 15.4 °C | 92.46 mm |
| November | -1.8 °C | 8.3 °C | 75.95 mm |
| December | -6.2 °C | 2.4 °C | 78.49 mm |
| Annual | 1.7 °C | 13.8 °C | 1048.02 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |