Today | Weather | Wednesday, December 24, 2025

Weather in St. Charles, Missouri

12:04 PM
Now
Cloudy Weather
57° F
Feels Like 55°
Precipitation 29 %
Wind 10 mph
UV Index (0 - 11+) 1
Humidity 79 %
Today
Rainy Weather
Day 64°
Night 54°
Precipitation 41 %
Wind 8 mph
UV Index (0 - 11+) 1

St. Charles Weather Forecast Updated

Last updated on

Air Quality in St. Charles

NOW
14 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 1.69 µg/m³
PM10 2.1 µg/m³
O3 0.016 ppm
NO2 1.1 ppb
SO2 0 ppb
CO 0.13 ppm
NH3 0.11 µg/m³
NO 0.36 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)
PM2.51.69 µg/m³
PM102.1 µg/m³
O330.66 µg/m³
NO22.13 µg/m³
SO20.09 µg/m³
CO150.22 µg/m³
NH30.11 µg/m³
NO0.36 µg/m³