Last updated: June 24, 2025
In May, the average temperature in Sioux City, United States reaches a comfortable 16°C (61°F). However, be prepared for a range of temperatures, as it can dip to a chilly 1°C (34°F) at night or soar to a warm 35°C (96°F) during the day. Expect about 140 mm (5.5 in) of rain distributed over 15 days, contributing to an average humidity of 74% that adds to the overall atmosphere.
In May in Sioux City, the average temperature is 16°C (61°F). Maximums can reach up to 35°C (96°F), while minimums can drop as low as 1°C (34°F). This variation in temperatures makes Sioux City an exciting destination for travelers seeking both warm days and cool nights.
In Sioux City in May, the total precipitation amount is 140 mm (5.5 in) over a span of 15 days.
In Sioux City in May humidity is 74%. With an average temperature of 16°C (61°F), this humidity feels like a damp blanket wrapping around you, making traveling quite uncomfortable as the air feels thick and muggy, potentially leading to fatigue and a longing for a cool breeze.
In Sioux City in May, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Sioux City.
UV Risk Categories
Weather in Sioux City varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in Sioux City, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -5°C (23°F) | 28 mm (1.1 inches) | 80% | moderate |
| February Weather | -5°C (23°F) | 29 mm (1.2 inches) | 84% | moderate |
| March Weather | 3°C (38°F) | 81 mm (3.2 inches) | 75% | moderate |
| April Weather | 9°C (48°F) | 80 mm (3.2 inches) | 79% | very high |
| May Weather | 16°C (61°F) | 140 mm (5.5 inches) | 74% | very high |
| June Weather | 23°C (74°F) | 102 mm (4.0 inches) | 81% | extreme |
| July Weather | 25°C (77°F) | 66 mm (2.6 inches) | 82% | very high |
| August Weather | 23°C (73°F) | 109 mm (4.3 inches) | 80% | very high |
| September Weather | 20°C (68°F) | 101 mm (4.0 inches) | 75% | very high |
| October Weather | 10°C (51°F) | 77 mm (3.0 inches) | 77% | moderate |
| November Weather | 3°C (38°F) | 27 mm (1.0 inches) | 85% | moderate |
| December Weather | -2°C (29°F) | 41 mm (1.6 inches) | 83% | low |