Machias, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.4 °C (low) to 12.8 °C (high). Annual precipitation averages 1166.6 Millimeters. Machias 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 | -10.7 °C | -1.3 °C | 88.65 mm |
| February | -10.4 °C | 0.1 °C | 66.04 mm |
| March | -6.7 °C | 4.6 °C | 78.49 mm |
| April | -0.4 °C | 12.1 °C | 91.95 mm |
| May | 5.9 °C | 19.1 °C | 97.79 mm |
| June | 10.8 °C | 23.4 °C | 113.03 mm |
| July | 13.1 °C | 25.6 °C | 115.32 mm |
| August | 12.1 °C | 24.9 °C | 106.43 mm |
| September | 8.6 °C | 21.3 °C | 107.95 mm |
| October | 2.9 °C | 14.5 °C | 107.95 mm |
| November | -2.1 °C | 7.4 °C | 96.77 mm |
| December | -6.6 °C | 1.6 °C | 96.27 mm |
| Annual | 1.4 °C | 12.8 °C | 1166.64 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 |