Clinton, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.4 °C (low) to 12.9 °C (high). Annual precipitation averages 1131.1 Millimeters. Clinton 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 | -1.9 °C | 82.04 mm |
| February | -12.4 °C | -0.2 °C | 69.85 mm |
| March | -6.5 °C | 4.7 °C | 87.63 mm |
| April | 0.1 °C | 11.8 °C | 97.54 mm |
| May | 6.2 °C | 18.7 °C | 88.39 mm |
| June | 11.6 °C | 23.6 °C | 104.39 mm |
| July | 14.8 °C | 26.6 °C | 86.11 mm |
| August | 13.9 °C | 26.1 °C | 89.66 mm |
| September | 9.5 °C | 21.9 °C | 94.23 mm |
| October | 3.5 °C | 14.7 °C | 125.73 mm |
| November | -2 °C | 7.7 °C | 102.87 mm |
| December | -8.3 °C | 1.4 °C | 102.62 mm |
| Annual | 1.4 °C | 12.9 °C | 1131.06 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 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |