| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F |
| Average First Frost Date: | Oct. 21 - Oct. 31 |
| Average Last Frost Date: | Apr. 21 - Apr. 30 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 55b - Loamy High Lime Till Plains |
| Heat Zone Days: | 46 - 60 days Over 86°F |
Annual Climate Data for ZIP Code 45014 - Fairfield, OH | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 20 | 24 | 32 | 41 | 51 | 60 | 64 | 62 | 54 | 43 | 34 | 26 | 43 |
| Avg Max Temp (°F) | 38 | 44 | 54 | 66 | 76 | 84 | 87 | 86 | 80 | 68 | 54 | 44 | 65 |
| Avg Precip (In.) | 2.9 | 2.6 | 3.59 | 3.94 | 4.73 | 4.05 | 4 | 3.7 | 2.96 | 2.93 | 3.49 | 3.11 | 42.01 |