Tri-Cities Ozone Forecast

Air Quality Today and Tomorrow

Sign up for ozone alerts

What this forecast means

If ozone is forecast to be in the yellow, orange or red category, high ozone levels are expected in the Tri-Cities area. Ozone is a toxic air pollutant that can harm your health.

What to do when high ozone is forecast

If high ozone levels are predicted for the Tri-Cities in the next two days, there are simple steps you can take to reduce ozone production and protect your health:

Department Of Ecology-Ozone Habits from PS MEDIA on Vimeo.

Reducing ozone

Protecting your health

(click for full PDF)

Health effects of ozone

Ground-level ozone can affect everyone, but people with lung disease, children, older adults, and physically active people are especially sensitive.

Air Quality FAQs
(click for full PDF)

Ground-level ozone can:

Why are ozone levels high in the Tri-Cities?

NOx and VOC sources High ozone levels in the Tri-Cities are really no one's fault, but there are small steps everyone who lives in the region can do to reduce levels of this toxic air pollutant.

On very hot summer days, two forms of air pollution – nitrogen oxides (NOx) and volatile organic compounds (VOCs) – combine in the atmosphere and are cooked by the sun, forming ozone. NOx and VOCs come from many sources, but cars and trucks are the largest contributors.

In the Tri-Cities area, prevailing summer winds push this ground-level ozone up against the Horse Heaven Hills, where it stacks up and becomes concentrated over the more populated areas.

Learn more about Tri-Cities ozone levels.

How the forecast tool works

This forecast is for ozone in the Kennewick and nearby areas. Developed by researchers at Washington State University in collaboration with the Washington Department of Ecology, the forecast tool is based on a novel machine learning approach that uses recent measured ozone levels together with forecast weather conditions to estimate ozone levels for a 72-hour forecast period.

The machine learning method trains a model using observed ozone levels from the past several years and then estimates next day ozone levels based on the patterns observed in recent years.

Click here for a technical explanation of the machine learning method

Recent observed and forecast ozone levels

Observed and forecast ozone levels


Find out more