Today | Weather | Tuesday, December 9, 2025

Weather in St. Louis, Missouri

07:16 PM
Now
Cloudy Weather
46° F
Feels Like 37°
Precipitation 0 %
Wind 16 mph
Humidity 62 %
Today
Cloudy Weather
Day 55°
Night 39°
Precipitation 0 %
Wind 12 mph
UV Index (0 - 11+) 2

St. Louis Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (December 9, 2024)
Cloudy Night

Day

55°

Night

37°

Wind

6 mph

Precipitation

6 %

Air Quality in St. Louis

NOW
35 AQI
Good air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 8.41 µg/m³
PM10 9.19 µg/m³
O3 0.038 ppm
NO2 1.3 ppb
SO2 0.4 ppb
CO 0.16 ppm
NH3 0.82 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)
PM2.58.41 µg/m³
PM109.19 µg/m³
O373.63 µg/m³
NO22.47 µg/m³
SO21.05 µg/m³
CO184.75 µg/m³
NH30.82 µg/m³
NO0 µg/m³