Fort Washington, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 48.2 °F (low) to 66.9 °F (high). Annual precipitation averages 45.3 Inches. Fort Washington is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 27.5 °F | 44.2 °F | 3.06 in. |
| February | 29.2 °F | 47.6 °F | 2.71 in. |
| March | 35.9 °F | 55.8 °F | 3.84 in. |
| April | 46.0 °F | 67.3 °F | 3.4 in. |
| May | 55.5 °F | 75.5 °F | 4.4 in. |
| June | 64.7 °F | 83.9 °F | 4.5 in. |
| July | 69.6 °F | 88.3 °F | 4.57 in. |
| August | 68.0 °F | 86.5 °F | 3.71 in. |
| September | 61.4 °F | 79.9 °F | 4.35 in. |
| October | 49.5 °F | 68.5 °F | 3.89 in. |
| November | 39.0 °F | 57.6 °F | 3.13 in. |
| December | 31.9 °F | 48.2 °F | 3.74 in. |
| Annual | 48.2 °F | 66.9 °F | 45.3 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 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 |