South Sioux City, Nebraska has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 37.6 °F (low) to 59.9 °F (high). Annual precipitation averages 29.3 Inches. South Sioux City 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 | 10.1 °F | 29.5 °F | 0.63 in. |
| February | 14.3 °F | 34.5 °F | 0.8 in. |
| March | 25.4 °F | 47.7 °F | 1.6 in. |
| April | 36.4 °F | 61.0 °F | 3.19 in. |
| May | 49.0 °F | 72.1 °F | 4.07 in. |
| June | 59.9 °F | 82.2 °F | 4.51 in. |
| July | 63.6 °F | 85.5 °F | 3.34 in. |
| August | 61.1 °F | 83.3 °F | 3.5 in. |
| September | 51.5 °F | 77.0 °F | 2.98 in. |
| October | 38.6 °F | 63.9 °F | 2.31 in. |
| November | 25.5 °F | 47.6 °F | 1.38 in. |
| December | 15.3 °F | 34.1 °F | 0.97 in. |
| Annual | 37.6 °F | 59.9 °F | 29.28 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 | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |