Calhoun, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.6 °C (low) to 22.1 °C (high). Annual precipitation averages 1334.5 Millimeters. Calhoun is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -0.7 °C | 10.7 °C | 123.19 mm |
| February | 0.7 °C | 12.9 °C | 124.97 mm |
| March | 4.3 °C | 17.6 °C | 137.67 mm |
| April | 8.6 °C | 22.5 °C | 107.7 mm |
| May | 13.8 °C | 26.6 °C | 99.31 mm |
| June | 18.4 °C | 30.3 °C | 105.41 mm |
| July | 20.3 °C | 32 °C | 104.14 mm |
| August | 19.8 °C | 31.6 °C | 90.93 mm |
| September | 16.3 °C | 28.8 °C | 101.35 mm |
| October | 9.4 °C | 23.1 °C | 93.22 mm |
| November | 3.6 °C | 16.9 °C | 114.81 mm |
| December | 0.9 °C | 12.1 °C | 131.83 mm |
| Annual | 9.6 °C | 22.1 °C | 1334.53 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |