| 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: | May 1 - May 10 |
| 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 52246 - Iowa City, IA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 13 | 18 | 29 | 40 | 51 | 61 | 65 | 63 | 55 | 43 | 30 | 18 | 41 |
| Avg Max Temp (°F) | 30 | 36 | 49 | 63 | 74 | 83 | 87 | 84 | 77 | 65 | 48 | 34 | 61 |
| Avg Precip (In.) | 1.11 | 1.15 | 2.34 | 3.68 | 4.47 | 4.74 | 4.46 | 4.74 | 3.47 | 2.73 | 2.43 | 1.55 | 36.87 |