Sanford, Maine has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36 °F (low) to 57.2 °F (high). Annual precipitation averages 50.8 Inches. Sanford is located in USDA Plant Hardiness Zone 5b. 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 | 12.1 °F | 31.7 °F | 3.63 in. |
| February | 13.6 °F | 34.5 °F | 3.58 in. |
| March | 22.6 °F | 42.5 °F | 4.62 in. |
| April | 33.1 °F | 55.7 °F | 4.39 in. |
| May | 43.6 °F | 67.0 °F | 3.79 in. |
| June | 53.5 °F | 75.8 °F | 4.55 in. |
| July | 59.1 °F | 81.3 °F | 4.1 in. |
| August | 57.4 °F | 80.2 °F | 3.8 in. |
| September | 49.8 °F | 72.7 °F | 4.03 in. |
| October | 38.4 °F | 59.9 °F | 5.18 in. |
| November | 29.3 °F | 48.0 °F | 4.52 in. |
| December | 19.5 °F | 37.3 °F | 4.64 in. |
| Annual | 36 °F | 57.2 °F | 50.83 in. |
| 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 5b : -15°F to -10°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 |