| 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 5a: -20F to -15F |
| Average First Frost Date: | Oct. 21 - Oct. 31 |
| Average Last Frost Date: | May 1 - May 10 |
| 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 60056 - Mount Prospect, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 14 | 19 | 28 | 38 | 48 | 57 | 63 | 62 | 54 | 42 | 31 | 20 | 40 |
| Avg Max Temp (°F) | 29 | 35 | 46 | 58 | 70 | 79 | 83 | 81 | 74 | 62 | 47 | 34 | 58 |
| Avg Precip (In.) | 1.7 | 1.54 | 2.53 | 3.71 | 3.59 | 3.97 | 3.7 | 4.51 | 3.37 | 2.62 | 2.99 | 2.31 | 36.54 |