Today | Weather | Monday, September 21, 2026

Weather in Sioux City, Iowa

12:56 PM
Now
Rainy Weather
57° F
Feels Like 52°
Precipitation 80 %
Wind 9 mph
UV Index (0 - 11+) 1
Humidity 92 %
Today
Rainy Weather
Day 57°
Night 54°
Precipitation 100 %
Wind 8 mph
UV Index (0 - 11+) 1

Sioux City Weather Forecast Updated

14 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (September 21, 2025)
Stormy Weather

Day

82°

Night

61°

Wind

7 mph

Precipitation

55 %

Air Quality in Sioux City

NOW
23 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 1.64 µg/m³
PM10 1.71 µg/m³
O3 0.025 ppm
NO2 1.2 ppb
SO2 0.1 ppb
CO 0.14 ppm
NH3 0.8 µg/m³
NO 0.06 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

Show raw pollutant concentrations (µg/m³)
PM2.51.64 µg/m³
PM101.71 µg/m³
O348.99 µg/m³
NO22.18 µg/m³
SO20.39 µg/m³
CO157.42 µg/m³
NH30.8 µg/m³
NO0.06 µg/m³