| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F | |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F | |
| Average First Frost Date: | Oct. 21 - Oct. 31 | |
| Average Last Frost Date: | Apr. 21 - Apr. 30 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 72d - Upper Mississippi Alluvial Plain | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 52627 - Fort Madison, IA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 16 | 21 | 32 | 43 | 54 | 63 | 68 | 66 | 57 | 46 | 33 | 21 | 43 |
| Avg Max Temp (°F) | 32 | 37 | 50 | 62 | 73 | 82 | 87 | 84 | 77 | 65 | 49 | 36 | 61 |
| Avg Precip (In.) | 1.35 | 1.54 | 2.96 | 3.62 | 4.86 | 4.21 | 4.39 | 3.64 | 3.82 | 2.81 | 2.95 | 2.18 | 38.33 |