Alexandria Bay, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.2 °F (low) to 54.6 °F (high). Annual precipitation averages 39.1 Inches. 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 | 10.8 °F | 27.8 °F | 3.06 in. |
| February | 11.6 °F | 30.0 °F | 2.45 in. |
| March | 21.3 °F | 38.7 °F | 2.63 in. |
| April | 34.3 °F | 52.5 °F | 3.22 in. |
| May | 46.1 °F | 65.6 °F | 3.16 in. |
| June | 55.7 °F | 74.0 °F | 3.39 in. |
| July | 61.1 °F | 79.0 °F | 3.21 in. |
| August | 59.8 °F | 78.5 °F | 3.23 in. |
| September | 52.1 °F | 71.3 °F | 3.51 in. |
| October | 41.7 °F | 58.0 °F | 4.47 in. |
| November | 31.4 °F | 46.1 °F | 3.5 in. |
| December | 20.4 °F | 34.2 °F | 3.25 in. |
| Annual | 37.2 °F | 54.6 °F | 39.08 in. |
| 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 : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |