Helenwood, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 44.4 °F (low) to 67.1 °F (high). Annual precipitation averages 58.4 Inches. Helenwood 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 25.4 °F | 45.0 °F | 4.78 in. |
| February | 27.8 °F | 49.2 °F | 5.17 in. |
| March | 34.2 °F | 57.8 °F | 5.74 in. |
| April | 42.8 °F | 68.6 °F | 5.29 in. |
| May | 52.5 °F | 76.2 °F | 4.86 in. |
| June | 60.1 °F | 82.6 °F | 5.12 in. |
| July | 64.2 °F | 85.5 °F | 5.91 in. |
| August | 62.9 °F | 84.9 °F | 4.34 in. |
| September | 56.1 °F | 79.9 °F | 4.03 in. |
| October | 43.8 °F | 69.7 °F | 3.3 in. |
| November | 33.8 °F | 57.7 °F | 4.01 in. |
| December | 29.0 °F | 48.5 °F | 5.83 in. |
| Annual | 44.4 °F | 67.1 °F | 58.38 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 |