Millsboro, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.7 °F (low) to 63.1 °F (high). Annual precipitation averages 42.2 Inches. Millsboro is located in USDA Plant Hardiness Zone 6b. 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 | 21.4 °F | 38.8 °F | 3.17 in. |
| February | 22.5 °F | 41.5 °F | 2.72 in. |
| March | 29.4 °F | 51.0 °F | 3.44 in. |
| April | 38.9 °F | 64.1 °F | 3.42 in. |
| May | 49.4 °F | 73.4 °F | 4.35 in. |
| June | 58.4 °F | 80.9 °F | 4.39 in. |
| July | 62.6 °F | 84.7 °F | 4.56 in. |
| August | 61.2 °F | 83.9 °F | 3.8 in. |
| September | 54.2 °F | 77.7 °F | 3.3 in. |
| October | 42.7 °F | 65.6 °F | 2.82 in. |
| November | 33.0 °F | 53.2 °F | 3.03 in. |
| December | 26.5 °F | 42.9 °F | 3.18 in. |
| Annual | 41.7 °F | 63.1 °F | 42.18 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |