Air Quality in Kent, Washington — Live

Live readings from PurpleAir sensors across Kent — with free alerts the moment the air turns.

Live Kent AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Kent and Renton, Auburn, Tukwila, Federal Way.

Kent sits on the floor of the Green River Valley, and the valley floor is where the freight goes. Interstate 5 runs along the western rim, State Route 167 — the Valley Freeway — runs the length of it, and between them is one of the densest concentrations of warehouses and distribution buildings in the country; the manufacturing and distribution market in Kent and the surrounding area ranks fourth in the United States. When the Washington Department of Ecology drew up its list of sixteen communities overburdened and highly impacted by air pollution, South King County made it, and Kent is named inside the boundary alongside Tukwila, Renton, Des Moines, SeaTac, Auburn, Algona, Pacific and Federal Way. Ecology's own description of the place is short and accurate: a corridor of manufacturing facilities, distribution centers, businesses and rail lines running north-south through the center of the community.

Canairy watches the sensors around your home, your kids' school, and everywhere else you care about, and tells you in plain English when the air changes enough to matter.

The valley floor is one long distribution corridor

Almost everything about the Kent Valley is built around moving goods. The Port of Tacoma is 17 miles away and the Port of Seattle 21; BNSF Railway and Union Pacific both run through the valley with direct access to the national network; Sea-Tac handles over a billion pounds of air cargo a year a few miles to the west. SR-167 and I-5 carry the drayage between all of it. Ecology identified the South King County community not just for short-term fine particle exposure but for cumulative criteria air pollution driven by PM2.5, ozone and nitrogen dioxide in some areas — nitrogen dioxide being the pollutant that tracks most closely with diesel engines and heavy traffic.

It is not warehouses end to end. The same Ecology report notes natural areas and agricultural land along the Green River, and much of Kent outside the valley floor — the East Hill and West Hill above it — is ordinary residential neighborhood. Where you live in Kent relative to the valley and the freeway makes a real difference to what you breathe, which is the argument for watching a sensor near your own address rather than a citywide figure.

What the Kent monitor read before it was switched off

The Puget Sound Clean Air Agency ran a PM2.5 monitor at James and Central until June 2023. Its last full year, 2022, was the worst on the record: a 24-hour 98th-percentile reading of 33.7 micrograms per cubic meter against a federal limit of 35, and an annual mean of 9.25 — over the federal annual standard of 9.0. Its three-year design value settled at 8.3, back under the line. Since the monitor was retired, the nearest regulatory reference point has been Auburn-29th Street, several miles south.

The Auburn numbers show how much of that was smoke rather than traffic. In 2022 the Auburn site's 24-hour 98th percentile was 38.5 micrograms per cubic meter, above the standard — but strip out the days when wildfire smoke pushed the 24-hour average past 35.4, and the figure drops to 26.2. By 2024 it was down to 16.0. Across 2022 to 2024 the South King County community averaged 3.7 days a year with air quality unhealthy for sensitive groups or worse, down from 6.3 days a year over 2020 to 2022. In 2025 Ecology installed three additional low-cost, high-accuracy PM2.5 sensors in the community using Climate Commitment Act funds.

Smoke, and the airport to the west

The honest summary of Kent's air is that traffic and industry set a slightly elevated everyday floor, and smoke causes the days you actually notice. Wildfire smoke does it in late summer, and wood smoke does it in the cold months — the Puget Sound Clean Air Agency issues a Stage 1 burn ban in King County when PM2.5 is predicted to exceed a 24-hour average of 35 micrograms per cubic meter within 48 hours, and those bans typically occur in the fall and winter and usually last a few days.

Sea-Tac is close enough that people ask about it. A two-year University of Washington study, MOV-UP, sampled air within 10 miles of the airport in the direction of aircraft flight and found that communities underneath and downwind of jets landing at Sea-Tac are exposed to a distinct kind of ultrafine particle associated with aircraft rather than roadways, spread over a wider area than road pollution is. The study did not name Kent as one of the affected communities, and ultrafine particles are not what a PurpleAir sensor or the AQI measures — so treat it as a real finding about the airport's surroundings, not a Kent number.

Kent air quality FAQ

Why is there smoke in Kent today?

In late summer it is almost always wildfire smoke carried in from fires elsewhere, and the monitoring data shows how much difference it makes: at the nearby Auburn site in 2022 the 24-hour 98th-percentile PM2.5 was 38.5 micrograms per cubic meter, but only 26.2 once wildfire-affected days are excluded. In the cold months it is more likely wood smoke from fireplaces and stoves, held near the ground by an inversion over the valley floor — which is when the Puget Sound Clean Air Agency issues its burn bans. If it smells like a campfire and the sky is clear elsewhere, it is usually local wood smoke rather than a distant fire.

What is the air quality in Kent right now?

This page shows the live AQI for Kent, calculated from PurpleAir sensors around the city and updated continuously. That matters more here than in most places, because the regulatory monitor at James and Central was switched off in June 2023 and the nearest official reference site is now in Auburn. A sensor on your own block is the closest thing Kent has to a local reading.

Do the warehouses and truck traffic make the air worse?

Ecology identified South King County — Kent included — as overburdened and highly impacted by air pollution partly for cumulative criteria air pollution driven by fine particles, ozone and nitrogen dioxide, and described the community as a corridor of manufacturing facilities, distribution centers, businesses and rail lines running north-south through its center. Nitrogen dioxide is the pollutant most closely tied to diesel engines. What the fine-particle monitors show, though, is that the worst individual days in Kent have been smoke days, not traffic days: the community averaged 3.7 days a year of unhealthy air from 2022 to 2024, down from 6.3 a year over the previous three-year window.

Does Sea-Tac airport affect the air in Kent?

The University of Washington's MOV-UP study sampled within 10 miles of Sea-Tac along aircraft flight paths and found that communities underneath and downwind of landing jets are exposed to a type of ultrafine particle distinctly associated with aircraft, over a larger area than roadway pollution covers. Kent was not named among the affected communities, and ultrafine particles are not captured by the AQI or by consumer sensors, so there is no Kent-specific figure to quote. The airport does sit inside the same South King County community that Ecology flagged, alongside SeaTac, Des Moines and Tukwila.

What AQI level is unhealthy?

Under the US EPA scale, AQI 0–50 is Good and 51–100 is Moderate. From 101 the air is Unhealthy for Sensitive Groups — kids, older adults, and people with asthma or heart conditions — and above 150 it's Unhealthy for everyone. Canairy translates these numbers into a plain-English verdict, like whether to close the windows or move a workout indoors.

Is Canairy free?

Yes. The Canairy app is free to download and includes live air quality for all your saved places, plain-English verdicts, and free push alerts when the air crosses your threshold. A paid plan adds extras like SMS text alerts.

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