Alexander, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.4 °C (low) to 13.7 °C (high). Annual precipitation averages 985 Millimeters. Alexander is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.9 °C | -0.2 °C | 69.6 mm |
| February | -8.4 °C | 0.8 °C | 53.09 mm |
| March | -4.7 °C | 5.4 °C | 67.31 mm |
| April | 1.4 °C | 12.8 °C | 78.74 mm |
| May | 7.9 °C | 19.8 °C | 83.57 mm |
| June | 13.1 °C | 24.4 °C | 98.81 mm |
| July | 15.6 °C | 26.5 °C | 93.73 mm |
| August | 14.6 °C | 26 °C | 91.69 mm |
| September | 10.7 °C | 22.3 °C | 92.2 mm |
| October | 5.1 °C | 15.3 °C | 102.36 mm |
| November | -0.2 °C | 8.5 °C | 81.79 mm |
| December | -5.1 °C | 2.7 °C | 72.14 mm |
| Annual | 3.4 °C | 13.7 °C | 985.03 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°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 |