Fairfield, Kentucky has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 45.3 °F (low) to 67 °F (high). Annual precipitation averages 50.1 Inches. Fairfield is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 24.2 °F | 42.5 °F | 3.58 in. |
| February | 27.2 °F | 47.0 °F | 3.73 in. |
| March | 34.2 °F | 56.4 °F | 4.74 in. |
| April | 44.0 °F | 67.9 °F | 4.86 in. |
| May | 54.3 °F | 76.7 °F | 5.39 in. |
| June | 62.4 °F | 84.8 °F | 5.11 in. |
| July | 66.0 °F | 87.5 °F | 4.47 in. |
| August | 64.3 °F | 87.2 °F | 3.31 in. |
| September | 57.2 °F | 81.7 °F | 3.61 in. |
| October | 45.7 °F | 70.0 °F | 3.61 in. |
| November | 35.1 °F | 56.6 °F | 3.56 in. |
| December | 28.5 °F | 46.0 °F | 4.16 in. |
| Annual | 45.3 °F | 67 °F | 50.13 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |