Waldoboro, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.3 °C (low) to 12.8 °C (high). Annual precipitation averages 1276.9 Millimeters. Waldoboro is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.2 °C | -0.9 °C | 102.11 mm |
| February | -10.2 °C | 0.8 °C | 91.44 mm |
| March | -5.1 °C | 5 °C | 111.76 mm |
| April | 0.6 °C | 11.6 °C | 114.05 mm |
| May | 6.4 °C | 17.6 °C | 95.76 mm |
| June | 11.6 °C | 22.4 °C | 111 mm |
| July | 14.9 °C | 25.7 °C | 86.36 mm |
| August | 14.3 °C | 25.3 °C | 81.28 mm |
| September | 10.3 °C | 21.3 °C | 105.16 mm |
| October | 4.3 °C | 14.6 °C | 136.4 mm |
| November | -1 °C | 8.3 °C | 119.13 mm |
| December | -6.8 °C | 2.4 °C | 122.43 mm |
| Annual | 2.3 °C | 12.8 °C | 1276.88 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°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 |