Cosby, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46.2 °F (low) to 68.9 °F (high). Annual precipitation averages 54 Inches. Cosby 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 Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 28.0 °F | 47.9 °F | 4.31 in. |
| February | 30.6 °F | 52.1 °F | 4.07 in. |
| March | 36.7 °F | 60.6 °F | 4.67 in. |
| April | 44.6 °F | 70.1 °F | 4.6 in. |
| May | 53.6 °F | 77.4 °F | 4.94 in. |
| June | 61.4 °F | 83.8 °F | 5.57 in. |
| July | 65.0 °F | 86.5 °F | 5.91 in. |
| August | 64.0 °F | 85.9 °F | 4.96 in. |
| September | 58.0 °F | 81.0 °F | 3.56 in. |
| October | 46.0 °F | 71.0 °F | 2.84 in. |
| November | 35.9 °F | 60.0 °F | 3.74 in. |
| December | 31.1 °F | 50.9 °F | 4.83 in. |
| Annual | 46.2 °F | 68.9 °F | 54 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 100-125 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 | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |