Bethel, Maine has a Subarctic With Cool Summers And Year Around Rainfall climate (Köppen classification: Dfc). Average annual temperatures range from 0.8 °C (low) to 12.1 °C (high). Annual precipitation averages 1203.5 Millimeters. Bethel 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 | -13.1 °C | -2.8 °C | 80.52 mm |
| February | -12.6 °C | -1.1 °C | 73.41 mm |
| March | -7.2 °C | 3.8 °C | 86.36 mm |
| April | -0.4 °C | 11.1 °C | 101.6 mm |
| May | 5.7 °C | 18.6 °C | 98.55 mm |
| June | 10.9 °C | 23.1 °C | 118.87 mm |
| July | 13.9 °C | 25.9 °C | 105.66 mm |
| August | 12.9 °C | 25.1 °C | 105.41 mm |
| September | 8.4 °C | 21.2 °C | 86.11 mm |
| October | 2.7 °C | 13.7 °C | 136.4 mm |
| November | -2.7 °C | 6.7 °C | 104.14 mm |
| December | -8.4 °C | 0.3 °C | 106.43 mm |
| Annual | 0.8 °C | 12.1 °C | 1203.46 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| 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 | Dfc - Subarctic With Cool Summers And Year Around Rainfall |