Dumfries, Virginia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46.8 °F (low) to 67.1 °F (high). Annual precipitation averages 43.1 Inches. Dumfries 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 | 26.3 °F | 44.8 °F | 3.05 in. |
| February | 27.9 °F | 48.1 °F | 2.63 in. |
| March | 34.6 °F | 56.0 °F | 3.75 in. |
| April | 44.8 °F | 67.6 °F | 3.08 in. |
| May | 54.7 °F | 75.4 °F | 3.86 in. |
| June | 63.6 °F | 83.7 °F | 4.17 in. |
| July | 68.5 °F | 88.2 °F | 4.39 in. |
| August | 66.6 °F | 86.2 °F | 3.71 in. |
| September | 59.9 °F | 79.8 °F | 4.24 in. |
| October | 47.4 °F | 68.7 °F | 3.64 in. |
| November | 36.5 °F | 57.9 °F | 3.09 in. |
| December | 30.2 °F | 48.9 °F | 3.49 in. |
| Annual | 46.8 °F | 67.1 °F | 43.1 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| 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 | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |