| 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 60051 - McHenry, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 11 | 16 | 26 | 36 | 47 | 56 | 62 | 61 | 52 | 41 | 30 | 18 | 38 |
| Avg Max Temp (°F) | 28 | 33 | 44 | 56 | 69 | 78 | 82 | 80 | 73 | 62 | 46 | 33 | 57 |
| Avg Precip (In.) | 1.64 | 1.41 | 2.35 | 3.7 | 3.62 | 4.21 | 3.91 | 4.42 | 3.45 | 2.54 | 2.85 | 2.08 | 36.19 |