St. Louis Good

St. Louis, Missouri

Updated: Mar 13, 2026, 10:00 AM

Good

Air quality is satisfactory, and air pollution poses little or no risk.

Current Weather

14.9°C

Temperature

27%

Humidity

mph wind

Overcast

Conditions

Pollutant Breakdown

PM2.5

µg/m³ · Fine particles

PM10

µg/m³ · Coarse particles

30.4

Ozone

ppb · Ground-level ozone

NO₂

ppb · Nitrogen dioxide

1.6

SO₂

ppb · Sulfur dioxide

3.4

ppm · Carbon monoxide

Dominant pollutant: O3

PM2.5 Forecast (next 7 days)

Wed

3/11

avg

Thu

3/12

avg

Fri

3/13

avg

Sat

3/14

avg

Sun

3/15

avg

Mon

3/16

avg

Tue

3/17

avg

Health Guidance

✅

General population: No restrictions. Enjoy outdoor activities.

✅

Sensitive groups: Air quality is good. Normal activities are fine.

💨

Keep windows closed if AQI is Unhealthy or above. Use HEPA air purifiers indoors.

Data from: Missouri Department of Natural Resources - Division of Environmental Quality, Air Now - US EPA, World Air Quality Index Project

Is the air safe in St. Louis today?

The current Air Quality Index (AQI) in St. Louis is 30, which is classified as "Good". Air quality is satisfactory, and air pollution poses little or no risk.

The AQI scale runs from 0 to 500. Values of 0–50 are Good, 51–100 are Moderate, 101–150 are Unhealthy for Sensitive Groups, 151–200 are Unhealthy, 201–300 are Very Unhealthy, and 301–500 are Hazardous.

Air quality in St. Louis, Missouri is monitored by local environmental agencies and reported through the World Air Quality Index project. Data is updated hourly and includes PM2.5, PM10, ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide.

AQI Scale Reference

0–50

Good

51–100

Moderate

101–150

Unhealthy for Sensitive Groups

151–200

Unhealthy

201–300

Very Unhealthy

301+

Hazardous