| 2023 Hardiness Zone: | Zone 5b: -15°F to -10°F | |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F | |
| 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: | 8 - 14 days Over 86°F |
Annual Climate Data for ZIP Code 50211 - Norwalk, IA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 11 | 17 | 28 | 39 | 50 | 60 | 65 | 62 | 53 | 41 | 28 | 16 | 39 |
| Avg Max Temp (°F) | 29 | 35 | 48 | 61 | 72 | 81 | 85 | 84 | 76 | 64 | 47 | 33 | 60 |
| Avg Precip (In.) | .98 | 1.13 | 2.19 | 3.54 | 4.35 | 4.64 | 4.23 | 4.17 | 3.33 | 2.65 | 2.13 | 1.27 | 34.61 |