| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F 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: | 47e - Steeply Rolling Loess Prairies | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 51566 - Red Oak, IA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 12 | 17 | 28 | 39 | 50 | 60 | 65 | 62 | 53 | 41 | 28 | 17 | 39 |
| Avg Max Temp (°F) | 32 | 39 | 51 | 64 | 75 | 85 | 88 | 86 | 79 | 66 | 48 | 35 | 62 |
| Avg Precip (In.) | .86 | 1.15 | 2.33 | 3.58 | 4.64 | 5.12 | 4.77 | 3.98 | 4.04 | 2.43 | 2.14 | 1.22 | 36.26 |