Today | Weather | Tuesday, January 13, 2026

Weather in St. Charles, Missouri

04:01 PM
Now
Cloudy Weather
57° F
Feels Like 54°
Precipitation 22 %
Wind 13 mph
UV Index (0 - 11+) 0
Humidity 45 %
Today
Partly Sunny with Showers
Day 63°
Night 36°
Precipitation 49 %
Wind 13 mph
UV Index (0 - 11+) 2

St. Charles Weather Forecast Updated

Last updated on

Air Quality in St. Charles

NOW
41 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 4.56 µg/m³
PM10 6.25 µg/m³
O3 0.045 ppm
NO2 1.4 ppb
SO2 0.5 ppb
CO 0.13 ppm
NH3 0.69 µg/m³
NO 0.1 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)
PM2.54.56 µg/m³
PM106.25 µg/m³
O387.72 µg/m³
NO22.56 µg/m³
SO21.39 µg/m³
CO147.06 µg/m³
NH30.69 µg/m³
NO0.1 µg/m³