| 2023 Hardiness Zone: | Zone 5b: -15°F to -10°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: | 47f - Rolling Loess Prairies |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 52778 - Wilton, IA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 11 | 17 | 28 | 39 | 50 | 60 | 64 | 62 | 53 | 42 | 30 | 18 | 40 |
| Avg Max Temp (°F) | 29 | 35 | 48 | 61 | 73 | 82 | 85 | 83 | 76 | 64 | 47 | 34 | 60 |
| Avg Precip (In.) | 1.3 | 1.33 | 2.54 | 3.48 | 4.25 | 4.4 | 4.11 | 4.36 | 3.47 | 2.69 | 2.56 | 1.91 | 36.4 |