Little Sioux, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.4 °C (low) to 16.1 °C (high). Annual precipitation averages 869.2 Millimeters. Little Sioux 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 | -11.6 °C | -0.7 °C | 18.8 mm |
| February | -9.4 °C | 2 °C | 24.38 mm |
| March | -3.3 °C | 9.4 °C | 49.53 mm |
| April | 2.8 °C | 16.8 °C | 91.95 mm |
| May | 9.7 °C | 22.7 °C | 117.6 mm |
| June | 15.8 °C | 28.3 °C | 129.79 mm |
| July | 17.8 °C | 30.2 °C | 97.54 mm |
| August | 16.2 °C | 28.8 °C | 108.46 mm |
| September | 11.1 °C | 25.5 °C | 95.76 mm |
| October | 3.8 °C | 18.2 °C | 62.99 mm |
| November | -3.2 °C | 9.6 °C | 39.37 mm |
| December | -8.8 °C | 1.8 °C | 33.02 mm |
| Annual | 3.4 °C | 16.1 °C | 869.19 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |