Leonardtown, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 48 °F (low) to 67.5 °F (high). Annual precipitation averages 45 Inches. Leonardtown is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 28.1 °F | 45.8 °F | 3.13 in. |
| February | 29.5 °F | 48.4 °F | 2.82 in. |
| March | 36.2 °F | 56.1 °F | 4.11 in. |
| April | 45.9 °F | 67.7 °F | 3.5 in. |
| May | 55.1 °F | 75.7 °F | 4.08 in. |
| June | 64.0 °F | 83.9 °F | 4.01 in. |
| July | 68.8 °F | 87.8 °F | 4.37 in. |
| August | 67.1 °F | 86.2 °F | 3.85 in. |
| September | 60.8 °F | 80.2 °F | 4.14 in. |
| October | 49.1 °F | 69.3 °F | 3.96 in. |
| November | 38.9 °F | 58.8 °F | 3.28 in. |
| December | 32.7 °F | 50.0 °F | 3.71 in. |
| Annual | 48 °F | 67.5 °F | 44.96 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7b : 5°F to 10°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |