Worst air pollution St. Louis, today and tomorrow
Today (30 August): Air quality in St. Louis is moderate. AQI and O3 are moderate; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 7:00 AM (O3: 41.2/100).
Tomorrow (31 August 2026): Air quality in St. Louis is fair. AQI improves to fair; O3 decreases to fair; all other pollutants stay as today. Pollution peaks around 7:00 AM (O3: 32.3/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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St. Louis' air quality reflects the Mississippi and Missouri river corridor's tendency to channel regional industrial and agricultural emissions, with the flat Midwest terrain providing limited topographic dispersal barriers. Summer ozone from vehicle emissions and upwind sources is the primary warm-season concern, while industrial emissions from the surrounding river corridor elevate baseline PM2.5 year-round.
Today - 30 August | Pollution peaks at 07:00
AQI:
Moderate
41.2/100
PM2.5 (fine particles):
Good
10.8/100
PM10 (coarse particles):
Good
10.1/100
NO2 (nitrogen dioxide):
Good
13.6/100
O3 (ozone):
Moderate
41.2/100
SO2 (sulfur dioxide):
Good
2.1/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
6.8/100
PM1 (ultrafine particles):
Good
6.7/100
Levels show the poorest local air quality during the day
Tomorrow - 31 August | Pollution peaks at 07:00
AQI:
Fair
32.3/100
PM2.5 (fine particles):
Good
12.9/100
PM10 (coarse particles):
Good
11.2/100
NO2 (nitrogen dioxide):
Good
10.4/100
O3 (ozone):
Fair
32.3/100
SO2 (sulfur dioxide):
Good
2.2/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
6.7/100
PM1 (ultrafine particles):
Good
6.7/100
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Frequently Asked Questions
Is air quality bad in St. Louis right now?
On 30 August 2026, overall air quality in St. Louis is moderate. AQI is the main air quality indicator at 41.2/100. Pollution peaks around 7:00 AM (O3: 41.2/100).
Will air quality be worse tomorrow in St. Louis?
On 31 August 2026, air quality conditions in St. Louis will be better than today, with AQI forecast at fair at 32.3/100. Pollution peaks around 7:00 AM (O3: 32.3/100).
When is air pollution at its worst in St. Louis?
Air quality across St. Louis rises and falls with the seasons, as the cleanest conditions usually come in winter, once the growing season dust and pollen have passed; by contrast, both spring planting and autumn harvest bring short bursts of elevated dust and smoke. Farm-heavy surrounding land is the main source of the seasonal dust spikes.
Are air quality levels in St. Louis based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
Why doesn’t the forecast always reflect wildfire impacts?
Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.
During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.
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Data provided by Airmine — Last update: 30 August 2026 at 20:26 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
Some text on this page may be generated or summarised using artificial intelligence (AI). Wherever possible, AI-generated content is enriched with Airmine's proprietary data to improve its accuracy and relevance. However, AI-generated content may still contain errors, omissions, or inaccuracies.
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