| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F | |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F | |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F | |
| Average First Frost Date: | Oct. 1 - Oct. 10 | |
| Average Last Frost Date: | May 1 - May 10 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 47e - Steeply Rolling Loess Prairies | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 8 - 14 days Over 86°F |
Annual Climate Data for ZIP Code 51401 - Carroll, IA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 7 | 13 | 24 | 35 | 48 | 58 | 63 | 60 | 50 | 38 | 25 | 13 | 36 |
| Avg Max Temp (°F) | 27 | 34 | 46 | 60 | 72 | 82 | 85 | 83 | 76 | 63 | 45 | 31 | 59 |
| Avg Precip (In.) | .88 | .84 | 2.26 | 3.38 | 4.35 | 4.58 | 4.72 | 3.74 | 3.28 | 2.46 | 1.76 | .97 | 33.22 |