Augusta, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36 °F (low) to 55.4 °F (high). Annual precipitation averages 46.3 Inches. Augusta is located in USDA Plant Hardiness Zone 5b. 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 | 10.6 °F | 29.4 °F | 3.46 in. |
| February | 12.3 °F | 32.4 °F | 2.98 in. |
| March | 22.2 °F | 40.7 °F | 3.69 in. |
| April | 33.2 °F | 53.3 °F | 4.15 in. |
| May | 43.9 °F | 64.9 °F | 3.36 in. |
| June | 53.5 °F | 73.7 °F | 4.21 in. |
| July | 59.5 °F | 79.5 °F | 3.26 in. |
| August | 58.1 °F | 78.7 °F | 3.43 in. |
| September | 50.5 °F | 71.3 °F | 3.86 in. |
| October | 39.5 °F | 58.5 °F | 5.32 in. |
| November | 29.6 °F | 46.3 °F | 4.35 in. |
| December | 18.9 °F | 35.5 °F | 4.26 in. |
| Annual | 36 °F | 55.4 °F | 46.33 in. |
| 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 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |