Worst air pollution Capitol Hill - Seattle, today and tomorrow

Today (15 July): Air quality in Capitol Hill is medium. AQI and O3 are medium; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 7:00 AM (O3: 52.9/100).
Tomorrow (16 July 2026): Air quality in Capitol Hill is medium. All pollutants stay as today. Pollution peaks around 4:00 AM (O3: 51.8/100). 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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Seattle's Capitol Hill records moderate Seattle air quality, shaped by dense residential and nightlife traffic on Broadway and surrounding streets and its valley position below First Hill. The neighbourhood's compact urban form limits natural dispersal, though prevailing southwesterlies keep conditions from deteriorating to the levels seen in industrial south Seattle.

Today - 15 July | Pollution peaks at 07:00

AQI:

Medium

52.9/100

PM2.5 (fine particles):

Good

11.8/100

PM10 (coarse particles):

Good

4.3/100

NO2 (nitrogen dioxide):

Good

14.9/100

O3 (ozone):

Medium

52.9/100

SO2 (sulfur dioxide):

Good

0.6/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

7.5/100

PM1 (ultrafine particles):

Good

14.4/100

Levels show the poorest local air quality during the day

Tomorrow - 16 July | Pollution peaks at 04:00

AQI:

Medium

51.8/100

PM2.5 (fine particles):

Good

10.0/100

PM10 (coarse particles):

Good

3.5/100

NO2 (nitrogen dioxide):

Good

10.4/100

O3 (ozone):

Medium

51.8/100

SO2 (sulfur dioxide):

Good

0.6/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

11.5/100

PM1 (ultrafine particles):

Good

12.3/100

Other Landmarks in Seattle

Sports venues in Seattle

Frequently Asked Questions

Is air quality bad in Capitol Hill right now?

On 15 July 2026, overall air quality in Capitol Hill is medium. AQI is the main air quality indicator at 52.9/100. Pollution peaks around 7:00 AM (O3: 52.9/100).

Will air quality be worse tomorrow in Capitol Hill?

On 16 July 2026, air quality conditions in Capitol Hill will be similar to today, with AQI forecast at medium at 51.8/100. Pollution peaks around 4:00 AM (O3: 51.8/100).

When is air pollution at its worst in Capitol Hill?

At Capitol Hill, air quality tends to follow Seattle's broader seasonal rhythm: rain-heavy winters keep the air unusually clean compared to much of the country, but the driest weeks of late summer bring the greatest risk of smoke drifting in from regional wildfires. Prevailing onshore winds usually keep pollution moving rather than letting it settle.

Are air quality levels in Capitol Hill 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.

Want to see air quality forecasts for other cities in United States?

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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