| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | Apr. 21 - Apr. 30 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 54f - Valparaiso-Wheaton Morainal Complex |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 60423 - Frankfort, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 14 | 19 | 29 | 38 | 49 | 59 | 63 | 62 | 54 | 43 | 32 | 20 | 40 |
| Avg Max Temp (°F) | 30 | 35 | 47 | 59 | 71 | 81 | 84 | 82 | 75 | 64 | 48 | 35 | 59 |
| Avg Precip (In.) | 1.68 | 1.57 | 2.67 | 3.81 | 4.17 | 4.6 | 4 | 3.84 | 3.27 | 2.89 | 3.33 | 2.55 | 38.4 |