Scarborough, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 40 °F (low) to 56 °F (high). Annual precipitation averages 48.4 Inches. Scarborough is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 17.3 °F | 32.5 °F | 3.53 in. |
| February | 18.5 °F | 34.8 °F | 3.55 in. |
| March | 26.4 °F | 41.5 °F | 4.28 in. |
| April | 36.6 °F | 52.9 °F | 4.36 in. |
| May | 46.5 °F | 63.3 °F | 3.6 in. |
| June | 56.0 °F | 72.9 °F | 4.26 in. |
| July | 61.9 °F | 78.6 °F | 3.53 in. |
| August | 61.1 °F | 78.0 °F | 3.41 in. |
| September | 53.7 °F | 70.9 °F | 3.86 in. |
| October | 43.2 °F | 59.4 °F | 5.15 in. |
| November | 33.9 °F | 48.4 °F | 4.27 in. |
| December | 24.3 °F | 38.5 °F | 4.62 in. |
| Annual | 40 °F | 56 °F | 48.42 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |