Charlton, Maryland has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.2 °F (low) to 64.8 °F (high). Annual precipitation averages 42.2 Inches. Charlton is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 23.0 °F | 40.8 °F | 2.94 in. |
| February | 24.3 °F | 44.3 °F | 2.35 in. |
| March | 31.2 °F | 52.9 °F | 3.58 in. |
| April | 41.3 °F | 65.1 °F | 3.61 in. |
| May | 50.9 °F | 73.9 °F | 4.32 in. |
| June | 59.7 °F | 82.7 °F | 4.19 in. |
| July | 64.3 °F | 87.3 °F | 3.68 in. |
| August | 62.6 °F | 85.5 °F | 3.74 in. |
| September | 55.5 °F | 78.7 °F | 4.04 in. |
| October | 43.8 °F | 66.8 °F | 3.45 in. |
| November | 34.2 °F | 55.2 °F | 2.91 in. |
| December | 27.0 °F | 44.4 °F | 3.35 in. |
| Annual | 43.2 °F | 64.8 °F | 42.16 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 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 | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |