Fallston, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 44.5 °F (low) to 65.9 °F (high). Annual precipitation averages 50 Inches. Fallston is located in USDA Plant Hardiness Zone 7b. 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 | 23.7 °F | 42.3 °F | 3.48 in. |
| February | 25.2 °F | 45.2 °F | 2.82 in. |
| March | 31.8 °F | 53.6 °F | 4.46 in. |
| April | 42.4 °F | 66.1 °F | 3.77 in. |
| May | 52.1 °F | 75.2 °F | 4.35 in. |
| June | 61.2 °F | 83.4 °F | 4.61 in. |
| July | 66.3 °F | 87.6 °F | 4.73 in. |
| August | 64.3 °F | 86.1 °F | 4.69 in. |
| September | 57.6 °F | 79.8 °F | 4.76 in. |
| October | 45.8 °F | 68.5 °F | 4.64 in. |
| November | 35.4 °F | 56.4 °F | 3.44 in. |
| December | 28.3 °F | 46.2 °F | 4.23 in. |
| Annual | 44.5 °F | 65.9 °F | 49.98 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |