Unicoi, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 6.7 °C (low) to 19.7 °C (high). Annual precipitation averages 1272.8 Millimeters. Unicoi 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 | -3.3 °C | 8.2 °C | 94.74 mm |
| February | -2.1 °C | 10.3 °C | 98.81 mm |
| March | 1.3 °C | 14.8 °C | 106.43 mm |
| April | 5.9 °C | 20.4 °C | 115.32 mm |
| May | 10.7 °C | 24.4 °C | 104.14 mm |
| June | 15.1 °C | 27.8 °C | 121.92 mm |
| July | 17.1 °C | 29.3 °C | 147.07 mm |
| August | 16.7 °C | 28.9 °C | 128.02 mm |
| September | 13.1 °C | 26.4 °C | 92.2 mm |
| October | 6.7 °C | 21.1 °C | 73.15 mm |
| November | 1.2 °C | 15.1 °C | 82.8 mm |
| December | -1.6 °C | 10.1 °C | 108.2 mm |
| Annual | 6.7 °C | 19.7 °C | 1272.8 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |