Fairburn, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.9 °C (low) to 22.2 °C (high). Annual precipitation averages 1354.3 Millimeters. Fairburn is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.4 °C | 11.7 °C | 123.7 mm |
| February | 2.1 °C | 13.9 °C | 123.95 mm |
| March | 5.8 °C | 18.2 °C | 131.83 mm |
| April | 10.1 °C | 22.6 °C | 108.2 mm |
| May | 15.2 °C | 26.4 °C | 95.76 mm |
| June | 19.4 °C | 29.7 °C | 108.97 mm |
| July | 21.2 °C | 31.4 °C | 131.06 mm |
| August | 20.8 °C | 30.9 °C | 112.01 mm |
| September | 17.6 °C | 28.1 °C | 100.08 mm |
| October | 11.3 °C | 22.9 °C | 88.65 mm |
| November | 5.2 °C | 17.4 °C | 105.66 mm |
| December | 2.1 °C | 13.1 °C | 124.46 mm |
| Annual | 10.9 °C | 22.2 °C | 1354.33 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°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 |