Today | Weather | Monday, September 14, 2026

Weather in St. Louis, Missouri

01:37 PM
Now
Sunny Weather
84° F
Feels Like 84°
Precipitation 0 %
Wind 15 mph
UV Index (0 - 11+) 5
Humidity 42 %
Today
Cloudy Weather
Day 88°
Night 70°
Precipitation 1 %
Wind 13 mph
UV Index (0 - 11+) 6

St. Louis Weather Forecast Updated

17 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (September 14, 2025)
Sunny with a Chance of Thunderstorms

Day

99°

Night

68°

Wind

4 mph

UV Index

60

Precipitation

49 %

Air Quality in St. Louis

NOW
44 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 7.45 µg/m³
PM10 8.12 µg/m³
O3 0.048 ppm
NO2 0.3 ppb
SO2 0.7 ppb
CO 0.12 ppm
NH3 0.52 µg/m³
NO 0.09 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)
PM2.57.45 µg/m³
PM108.12 µg/m³
O393.53 µg/m³
NO20.53 µg/m³
SO21.84 µg/m³
CO132.37 µg/m³
NH30.52 µg/m³
NO0.09 µg/m³