Harriston, Virginia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 43.7 °F (low) to 66.1 °F (high). Annual precipitation averages 42.4 Inches. Harriston is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 24.2 °F | 44.2 °F | 3.01 in. |
| February | 26.3 °F | 47.6 °F | 2.29 in. |
| March | 32.3 °F | 55.5 °F | 3.56 in. |
| April | 42.0 °F | 67.1 °F | 3.53 in. |
| May | 51.7 °F | 74.7 °F | 3.94 in. |
| June | 60.5 °F | 82.6 °F | 4.12 in. |
| July | 64.4 °F | 86.0 °F | 3.93 in. |
| August | 62.8 °F | 84.7 °F | 3.42 in. |
| September | 55.7 °F | 78.4 °F | 4.95 in. |
| October | 43.9 °F | 68.0 °F | 3.27 in. |
| November | 33.5 °F | 57.0 °F | 3.3 in. |
| December | 27.5 °F | 47.5 °F | 3.11 in. |
| Annual | 43.7 °F | 66.1 °F | 42.43 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |