Calhoun, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.7 °C (low) to 21.3 °C (high). Annual precipitation averages 1475 Millimeters. Calhoun is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -1.8 °C | 9.3 °C | 137.92 mm |
| February | -0.4 °C | 11.8 °C | 123.19 mm |
| March | 3.1 °C | 16.6 °C | 144.53 mm |
| April | 7.6 °C | 21.9 °C | 126.75 mm |
| May | 13.1 °C | 26.1 °C | 112.01 mm |
| June | 17.6 °C | 29.8 °C | 123.19 mm |
| July | 19.8 °C | 31.4 °C | 141.48 mm |
| August | 19.2 °C | 31.2 °C | 98.3 mm |
| September | 15.4 °C | 28.4 °C | 119.89 mm |
| October | 8.4 °C | 22.6 °C | 82.3 mm |
| November | 2.2 °C | 16.1 °C | 119.38 mm |
| December | -0.3 °C | 10.9 °C | 146.05 mm |
| Annual | 8.7 °C | 21.3 °C | 1474.99 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |