| 2023 Hardiness Zone: | Zone 5b: -15°F to -10°F | |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°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: | 47f - Rolling Loess Prairies | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 50273 - Winterset, IA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 9 | 15 | 26 | 37 | 50 | 59 | 64 | 62 | 52 | 40 | 27 | 15 | 38 |
| Avg Max Temp (°F) | 29 | 35 | 48 | 61 | 71 | 80 | 85 | 83 | 76 | 64 | 47 | 33 | 59 |
| Avg Precip (In.) | .94 | 1.07 | 2.23 | 3.5 | 4.3 | 4.66 | 4.24 | 3.94 | 3.68 | 2.55 | 2.23 | 1.17 | 34.51 |