Alexandria Bay, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.9 °C (low) to 12.6 °C (high). Annual precipitation averages 992.6 Millimeters. Alexandria Bay 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 | -11.8 °C | -2.3 °C | 77.72 mm |
| February | -11.3 °C | -1.1 °C | 62.23 mm |
| March | -5.9 °C | 3.7 °C | 66.8 mm |
| April | 1.3 °C | 11.4 °C | 81.79 mm |
| May | 7.8 °C | 18.7 °C | 80.26 mm |
| June | 13.2 °C | 23.3 °C | 86.11 mm |
| July | 16.2 °C | 26.1 °C | 81.53 mm |
| August | 15.4 °C | 25.8 °C | 82.04 mm |
| September | 11.2 °C | 21.8 °C | 89.15 mm |
| October | 5.4 °C | 14.4 °C | 113.54 mm |
| November | -0.3 °C | 7.8 °C | 88.9 mm |
| December | -6.4 °C | 1.2 °C | 82.55 mm |
| Annual | 2.9 °C | 12.6 °C | 992.62 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 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 |