| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F |
| Average First Frost Date: | Oct. 1 - Oct. 10 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 47b - Des Moines Lobe |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 50428 - Clear Lake, IA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 5 | 11 | 23 | 35 | 47 | 57 | 61 | 59 | 49 | 37 | 24 | 10 | 35 |
| Avg Max Temp (°F) | 23 | 29 | 42 | 57 | 70 | 80 | 83 | 80 | 73 | 60 | 41 | 27 | 55 |
| Avg Precip (In.) | .95 | .84 | 2.1 | 3.31 | 4.25 | 4.95 | 4.35 | 4.52 | 3.27 | 2.44 | 1.98 | 1.08 | 34.05 |