| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°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: | 71d - Outer Bluegrass |
| Heat Zone Days: | 8 - 14 days Over 86°F |
Annual Climate Data for ZIP Code 41091 - Union, KY | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 21 | 25 | 33 | 42 | 52 | 61 | 65 | 64 | 56 | 45 | 36 | 26 | 44 |
| Avg Max Temp (°F) | 38 | 43 | 54 | 65 | 74 | 82 | 86 | 85 | 78 | 67 | 54 | 43 | 64 |
| Avg Precip (In.) | 3.06 | 2.82 | 4.05 | 4.01 | 4.73 | 4.36 | 4.03 | 3.82 | 2.98 | 2.97 | 3.56 | 3.35 | 43.75 |