Sioux City Climate: Weather by Month and Best Time to Visit
Best months for Sioux City: September, August, July.
Year at a glance
Weather by month
| Month | Avg high | Avg low | Rainfall | Rainy days | Humidity | Sunshine | Score |
|---|---|---|---|---|---|---|---|
| January | -1°C | -10°C | 23 mm | 5 | – | – | 4.4 |
| February | 2°C | -8°C | 27 mm | 5 | – | – | 4.5 |
| March | 9°C | -2°C | 55 mm | 7 | – | – | 5.8 |
| April | 17°C | 4°C | 100 mm | 11 | – | – | 6.7 |
| May | 22°C | 11°C | 126 mm | 13 | – | – | 7.2 |
| June | 28°C | 17°C | 123 mm | 12 | – | – | 7.3 |
| July | 30°C | 19°C | 76 mm | 9 | – | – | 7.7 |
| August | 28°C | 17°C | 98 mm | 9 | – | – | 7.8 |
| September | 25°C | 13°C | 76 mm | 8 | – | – | 8.1 |
| October | 17°C | 6°C | 61 mm | 7 | – | – | 7.4 |
| November | 9°C | -2°C | 40 mm | 6 | – | – | 5.9 |
| December | 1°C | -8°C | 30 mm | 5 | – | – | 4.4 |