Worst air pollution Multnomah Falls - Portland, today and tomorrow

Today (9 August): Air quality in Multnomah Falls is fair. AQI, NO2, and O3 are fair; PM2.5, PM10, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 6:00 AM (O3: 37.5/100).
Tomorrow (10 August 2026): Air quality in Multnomah Falls is fair. All pollutants stay as today. Pollution peaks around 8:00 AM (O3: 35.9/100). 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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Portland's Multnomah Falls air quality benefits from the Columbia River Gorge's powerful channelled winds, with the Gorge's consistent easterly and westerly winds providing reliable and often dramatic ventilation at the base of the 189-metre waterfall. Vehicle traffic on the Historic Columbia River Highway contributes modest local sources, while the Gorge's powerful natural wind acceleration and the waterfall's misting provide natural atmospheric conditions and summer wildfire smoke is the primary seasonal concern throughout the year.

Today - 9 August | Pollution peaks at 06:00

AQI:

Fair

37.5/100

PM2.5 (fine particles):

Good

9.8/100

PM10 (coarse particles):

Good

6.4/100

NO2 (nitrogen dioxide):

Fair

25.7/100

O3 (ozone):

Fair

37.5/100

SO2 (sulfur dioxide):

Good

1.8/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

9.7/100

PM1 (ultrafine particles):

Good

6.8/100

Levels show the poorest local air quality during the day

Tomorrow - 10 August | Pollution peaks at 08:00

AQI:

Fair

35.9/100

PM2.5 (fine particles):

Good

12.6/100

PM10 (coarse particles):

Good

8.0/100

NO2 (nitrogen dioxide):

Fair

30.7/100

O3 (ozone):

Fair

35.9/100

SO2 (sulfur dioxide):

Good

1.5/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

6.8/100

PM1 (ultrafine particles):

Good

9.7/100

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Frequently Asked Questions

Is air quality bad in Multnomah Falls right now?

On 9 August 2026, overall air quality in Multnomah Falls is fair. AQI is the main air quality indicator at 37.5/100. Pollution peaks around 6:00 AM (O3: 37.5/100).

Will air quality be worse tomorrow in Multnomah Falls?

On 10 August 2026, air quality conditions in Multnomah Falls will be similar to today, with AQI forecast at fair at 35.9/100. Pollution peaks around 8:00 AM (O3: 35.9/100).

When is air pollution at its worst in Multnomah Falls?

Air quality at Multnomah Falls shifts across the year, as winter and spring bring the cleanest air, as frequent rain and consistent onshore wind clear pollution quickly; by contrast, the driest weeks of late summer bring the greatest risk of smoke drifting in from regional wildfires. Coastal areas see relatively little of the smoke that can settle into inland valleys during fire season.

Are air quality levels in Multnomah Falls 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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