| 2023 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | May 1 - May 10 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 53b - Kettle Moraines |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 60030 - Grayslake, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 12 | 16 | 26 | 37 | 47 | 56 | 62 | 61 | 52 | 41 | 30 | 18 | 38 |
| Avg Max Temp (°F) | 28 | 33 | 44 | 56 | 69 | 79 | 83 | 81 | 73 | 62 | 46 | 33 | 57 |
| Avg Precip (In.) | 1.64 | 1.4 | 2.3 | 3.71 | 3.55 | 4.06 | 3.81 | 4.39 | 3.44 | 2.49 | 2.78 | 2.07 | 35.65 |