Machiasport, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.3 °C (low) to 11 °C (high). Annual precipitation averages 1312.4 Millimeters. Machiasport is located in USDA Plant Hardiness Zone 5b. 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 | -9.4 °C | -0.6 °C | 116.59 mm |
| February | -8.8 °C | 0 °C | 94.49 mm |
| March | -4.9 °C | 3.6 °C | 115.82 mm |
| April | 0.7 °C | 8.8 °C | 106.93 mm |
| May | 5.2 °C | 14.1 °C | 101.35 mm |
| June | 9.4 °C | 19 °C | 99.31 mm |
| July | 12.4 °C | 21.9 °C | 86.87 mm |
| August | 12.7 °C | 22 °C | 81.53 mm |
| September | 9.9 °C | 19.1 °C | 101.85 mm |
| October | 5.1 °C | 13.4 °C | 139.95 mm |
| November | 0.1 °C | 7.8 °C | 131.32 mm |
| December | -5.2 °C | 2.9 °C | 136.4 mm |
| Annual | 2.3 °C | 11 °C | 1312.41 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |