| 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: | 47b - Des Moines Lobe |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 50226 - Polk City, IA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 9 | 15 | 26 | 38 | 50 | 59 | 64 | 61 | 52 | 40 | 27 | 15 | 38 |
| Avg Max Temp (°F) | 28 | 34 | 47 | 60 | 72 | 81 | 85 | 83 | 76 | 64 | 46 | 32 | 59 |
| Avg Precip (In.) | .85 | .98 | 2.13 | 3.34 | 4.34 | 4.96 | 4.24 | 4.2 | 3.17 | 2.55 | 2.01 | 1.12 | 33.9 |