| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| 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: | 54b - Chicago Lake Plain |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 60409 - Calumet City, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 16 | 21 | 30 | 39 | 50 | 60 | 65 | 63 | 55 | 44 | 33 | 22 | 41 |
| Avg Max Temp (°F) | 31 | 36 | 47 | 59 | 70 | 80 | 84 | 82 | 76 | 64 | 49 | 36 | 59 |
| Avg Precip (In.) | 1.93 | 1.65 | 2.75 | 3.69 | 3.89 | 4.36 | 3.78 | 3.81 | 3.41 | 2.85 | 3.32 | 2.63 | 38.07 |