Au Sable Forks, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.8 °C (low) to 12.7 °C (high). Annual precipitation averages 901.5 Millimeters. Au Sable Forks 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 | -12.9 °C | -2.7 °C | 53.09 mm |
| February | -11.8 °C | -0.9 °C | 46.23 mm |
| March | -6.6 °C | 3.9 °C | 60.45 mm |
| April | 0.6 °C | 11.9 °C | 71.37 mm |
| May | 7.1 °C | 19.4 °C | 79.76 mm |
| June | 12.3 °C | 24.2 °C | 110.24 mm |
| July | 15.1 °C | 26.9 °C | 92.71 mm |
| August | 14.1 °C | 25.9 °C | 87.38 mm |
| September | 9.8 °C | 21.9 °C | 76.71 mm |
| October | 3.7 °C | 14.3 °C | 94.23 mm |
| November | -1.9 °C | 7.1 °C | 68.33 mm |
| December | -8.1 °C | 0.8 °C | 60.96 mm |
| Annual | 1.8 °C | 12.7 °C | 901.46 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 |