| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°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: | Apr. 21 - Apr. 30 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 40a - Loess Flats and Till Plains |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 52625 - Donnellson, IA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 14 | 20 | 31 | 41 | 52 | 62 | 66 | 64 | 55 | 44 | 32 | 20 | 42 |
| Avg Max Temp (°F) | 32 | 38 | 50 | 63 | 73 | 82 | 87 | 85 | 77 | 66 | 49 | 36 | 61 |
| Avg Precip (In.) | 1.54 | 1.49 | 2.93 | 3.55 | 4.64 | 4.21 | 4.33 | 3.83 | 3.78 | 2.82 | 3.03 | 2.16 | 38.3 |