| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 21 - Oct. 31 |
| Average Last Frost Date: | Apr. 11 - Apr. 20 |
| 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 60621 - Chicago, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 18 | 23 | 32 | 41 | 51 | 60 | 66 | 65 | 57 | 46 | 35 | 23 | 43 |
| Avg Max Temp (°F) | 32 | 37 | 47 | 59 | 70 | 80 | 85 | 83 | 76 | 64 | 50 | 37 | 60 |
| Avg Precip (In.) | 2.13 | 1.76 | 2.97 | 3.68 | 3.73 | 4.27 | 3.71 | 3.9 | 3.25 | 2.71 | 3.3 | 2.64 | 38.04 |