Fairfield, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.8 °C (low) to 20.1 °C (high). Annual precipitation averages 1337.3 Millimeters. Fairfield 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 | -2.6 °C | 7.2 °C | 102.87 mm |
| February | -1 °C | 9.8 °C | 114.3 mm |
| March | 3.1 °C | 14.8 °C | 126.24 mm |
| April | 8 °C | 20.7 °C | 121.16 mm |
| May | 13.7 °C | 25 °C | 138.43 mm |
| June | 18.1 °C | 29.2 °C | 114.05 mm |
| July | 20.1 °C | 30.9 °C | 118.62 mm |
| August | 19.3 °C | 30.7 °C | 97.28 mm |
| September | 15.3 °C | 27.6 °C | 97.03 mm |
| October | 8.8 °C | 21.6 °C | 90.68 mm |
| November | 3 °C | 14.6 °C | 95.25 mm |
| December | -0.3 °C | 9.2 °C | 121.41 mm |
| Annual | 8.8 °C | 20.1 °C | 1337.32 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 | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |