Worst air pollution Capitol Hill - Seattle, today and tomorrow
Today (9 August): Air quality in Capitol Hill is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 5:00 AM (O3: 37.8/100).
Tomorrow (10 August 2026): Air quality in Capitol Hill is fair. All pollutants stay as today. Pollution peaks around 10:00 AM (O3: 24.8/100). Airmine updates local air quality forecasts four times daily.
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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 - 9 August | Pollution peaks at 05:00
AQI:
Fair
37.8/100
PM2.5 (fine particles):
Good
8.8/100
PM10 (coarse particles):
Good
6.9/100
NO2 (nitrogen dioxide):
Good
3.2/100
O3 (ozone):
Fair
37.8/100
SO2 (sulfur dioxide):
Good
0.7/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
8.3/100
PM1 (ultrafine particles):
Good
4.5/100
Levels show the poorest local air quality during the day
Tomorrow - 10 August | Pollution peaks at 10:00
AQI:
Fair
24.8/100
PM2.5 (fine particles):
Good
4.7/100
PM10 (coarse particles):
Good
3.1/100
NO2 (nitrogen dioxide):
Good
3.3/100
O3 (ozone):
Fair
24.8/100
SO2 (sulfur dioxide):
Good
0.8/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
4.1/100
PM1 (ultrafine particles):
Good
3.3/100
Other Landmarks in Seattle
Sports venues in Seattle
Frequently Asked Questions
Is air quality bad in Capitol Hill right now?
On 9 August 2026, overall air quality in Capitol Hill is fair. AQI is the main air quality indicator at 37.8/100. Pollution peaks around 5:00 AM (O3: 37.8/100).
Will air quality be worse tomorrow in Capitol Hill?
On 10 August 2026, air quality conditions in Capitol Hill will be similar to today, with AQI forecast at fair at 24.8/100. Pollution peaks around 10:00 AM (O3: 24.8/100).
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.
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: 10 August 2026 at 02:34 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.
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