Fairbank, Iowa has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36.8 °F (low) to 56.9 °F (high). Annual precipitation averages 37.4 Inches. Fairbank is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 8.8 °F | 26.0 °F | 1.14 in. |
| February | 12.8 °F | 30.2 °F | 1.18 in. |
| March | 24.5 °F | 43.5 °F | 1.94 in. |
| April | 36.0 °F | 58.2 °F | 3.75 in. |
| May | 48.1 °F | 69.9 °F | 4.71 in. |
| June | 58.8 °F | 79.5 °F | 5.73 in. |
| July | 62.0 °F | 82.4 °F | 4.76 in. |
| August | 59.3 °F | 80.5 °F | 4.26 in. |
| September | 50.7 °F | 74.6 °F | 3.73 in. |
| October | 38.5 °F | 61.4 °F | 2.77 in. |
| November | 26.4 °F | 45.0 °F | 1.9 in. |
| December | 15.5 °F | 31.7 °F | 1.57 in. |
| Annual | 36.8 °F | 56.9 °F | 37.44 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |