Today | Weather | Sunday, November 1, 2026

Weather in O'Fallon, Missouri

10:32 PM
Now
Cloudy Weather
59° F
Feels Like 55°
Precipitation 9 %
Wind 7 mph
Humidity 90 %
Today
Cloudy Weather
Day 63°
Night 57°
Precipitation 25 %
Wind 7 mph

O'Fallon Weather Forecast Updated

19 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (November 1, 2025)
Cloudy Night

Day

52°

Night

34°

Wind

5 mph

Precipitation

25 %

Air Quality in O'Fallon

NOW
26 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 4.38 µg/m³
PM10 4.55 µg/m³
O3 0.028 ppm
NO2 1 ppb
SO2 0.2 ppb
CO 0.15 ppm
NH3 0.06 µg/m³
NO 0 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)
PM2.5 – 4.38 µg/m³
PM10 – 4.55 µg/m³
O3 – 55.19 µg/m³
NO2 – 1.94 µg/m³
SO2 – 0.58 µg/m³
CO – 167.13 µg/m³
NH3 – 0.06 µg/m³
NO – 0 µg/m³