Westernport, Maryland has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 41.2 °F (low) to 63.9 °F (high). Annual precipitation averages 40.9 Inches. Westernport is located in USDA Plant Hardiness Zone 7a. 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 | 22.2 °F | 39.3 °F | 2.79 in. |
| February | 23.3 °F | 42.8 °F | 2.8 in. |
| March | 29.8 °F | 51.5 °F | 3.71 in. |
| April | 38.9 °F | 65.5 °F | 3.58 in. |
| May | 48.2 °F | 74.1 °F | 4.35 in. |
| June | 57.2 °F | 81.6 °F | 4.15 in. |
| July | 61.4 °F | 85.8 °F | 3.97 in. |
| August | 60.0 °F | 84.6 °F | 3.48 in. |
| September | 53.1 °F | 78.2 °F | 3.76 in. |
| October | 42.1 °F | 66.2 °F | 2.92 in. |
| November | 32.5 °F | 53.6 °F | 2.48 in. |
| December | 26.1 °F | 43.2 °F | 2.95 in. |
| Annual | 41.2 °F | 63.9 °F | 40.94 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 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |