Mattawamkeag, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.6 °C (low) to 12.1 °C (high). Annual precipitation averages 1175.3 Millimeters. Mattawamkeag is located in USDA Plant Hardiness Zone 5a. 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 | -15.8 °C | -3.3 °C | 92.71 mm |
| February | -15.3 °C | -1.4 °C | 75.44 mm |
| March | -8.8 °C | 3.6 °C | 92.96 mm |
| April | -1.7 °C | 10.6 °C | 93.22 mm |
| May | 4.4 °C | 18 °C | 93.73 mm |
| June | 9.7 °C | 23.1 °C | 107.44 mm |
| July | 13.2 °C | 26.2 °C | 93.98 mm |
| August | 11.9 °C | 25.8 °C | 88.14 mm |
| September | 7.5 °C | 21.4 °C | 92.2 mm |
| October | 1.4 °C | 14 °C | 123.44 mm |
| November | -3.6 °C | 6.7 °C | 108.71 mm |
| December | -10.3 °C | 0.4 °C | 113.28 mm |
| Annual | -0.6 °C | 12.1 °C | 1175.25 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 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 |