Worst air pollution St. George, today and tomorrow

Today (16 July): Air quality in St. George is medium. AQI and O3 are medium; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 10:00 AM (O3: 44.7/100).
Tomorrow (17 July 2026): Air quality in St. George is fair. AQI worsens to fair; O3 increases to fair; all other pollutants stay as today. Pollution peaks around 11:00 AM (O3: 38.5/100). 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. George's air quality in Utah reflects the Virgin River valley's partial topographic enclosure between the Pine Valley Mountains and the Red Cliffs desert landscape, with vehicle emissions from I-15 and the surrounding rapid residential and tourism development contributing local sources. Winter temperature inversions in the Washington County basin can concentrate vehicle and wood-burning emissions, while summer ozone from vehicle traffic and the intense Utah desert heat are the primary warm-season concerns in this rapidly growing southwestern Utah gateway city.

Today - 16 July | Pollution peaks at 10:00

AQI:

Medium

44.7/100

PM2.5 (fine particles):

Good

19.8/100

PM10 (coarse particles):

Good

9.9/100

NO2 (nitrogen dioxide):

Good

14.8/100

O3 (ozone):

Medium

44.7/100

SO2 (sulfur dioxide):

Good

2.7/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

2.2/100

PM1 (ultrafine particles):

Good

12.6/100

Levels show the poorest local air quality during the day

Tomorrow - 17 July | Pollution peaks at 11:00

AQI:

Fair

38.5/100

PM2.5 (fine particles):

Good

18.3/100

PM10 (coarse particles):

Good

7.5/100

NO2 (nitrogen dioxide):

Good

13.8/100

O3 (ozone):

Fair

38.5/100

SO2 (sulfur dioxide):

Good

3.9/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

2.3/100

PM1 (ultrafine particles):

Good

10.2/100

Pollen forecast in St. George

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Frequently Asked Questions

Is air quality bad in St. George right now?

On 16 July 2026, overall air quality in St. George is medium. AQI is the main air quality indicator at 44.7/100. Pollution peaks around 10:00 AM (O3: 44.7/100).

Will air quality be worse tomorrow in St. George?

On 17 July 2026, air quality conditions in St. George will be worse than today, with AQI forecast at fair at 38.5/100. Pollution peaks around 11:00 AM (O3: 38.5/100).

When is air pollution at its worst in St. George?

Conditions in St. George vary noticeably across the seasons: autumn is often the cleanest stretch, between wildfire season and the onset of winter inversions, but summer brings regional wildfire smoke, while winter brings its own inversion-driven pollution episodes. Valley and basin locations are especially prone to these winter inversion episodes compared to more exposed, higher terrain.

Are air quality levels in St. George 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.

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Data provided by Airmine — Last update: 16 July 2026 at 10:33 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.

For long term forecasts and maps, see the Airmine app