Air Quality in Renton, Washington — Live

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

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

Renton sits at 85 feet above sea level where the Cedar River empties into the south end of Lake Washington, with the flank of Cougar Mountain rising to the north and the East Renton Plateau climbing behind it. Unlike most of its neighbors, the things that shape Renton's air are almost all local and almost all built: two freeways that cross in the middle of town, two factories large enough to need federal air operating permits, and a regional landfill nine miles up the Cedar River valley. On an ordinary day none of them push the numbers far, which is worth saying plainly. But they are the reason a reading taken next to Rainier Avenue and a reading taken on the plateau are not the same reading.

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.

Two freeways cross in the middle of town

Interstate 405 runs north-south through Renton, and State Route 167 crosses it here on its way up the Green River Valley from Tacoma. SR 167 does not end at the interchange either. It carries on north through Renton as a six-lane stretch of Rainier Avenue before finishing at SR 900. WSDOT's own description of the I-405 corridor is blunt: travelers on Interstate 405 between Renton and Bellevue experience one of the state's worst commutes, and the agency has been widening and rebuilding it, including a redesigned NE 44th Street interchange, since 2015.

The traffic on SR 167 is not just commuters. About 8 percent of it is freight serving the industrial areas of the Green River Valley, and peak daily volumes on the highway reach around 129,000 vehicles. Diesel exhaust is a fine-particle and nitrogen dioxide source that falls off sharply with distance from the road, so the practical effect in Renton is that the closer a home, school or park is to the 405/167 knot, the more the local sensor is worth checking rather than a citywide average.

Boeing and Kenworth both hold air operating permits here

Only a couple of dozen facilities in the whole four-county Puget Sound region are large enough to need a Title V air operating permit, which is the federal permit reserved for major sources of air pollution. Two of them are in Renton. The Puget Sound Clean Air Agency lists Boeing (Renton), whose permit was renewed on December 11, 2017 and administratively amended several times since, most recently in March 2024, and Kenworth Truck Company, the truck plant on the valley floor.

The Boeing site is the 737 line. It is about 1,100,000 square feet of floor space next to Renton Municipal Airport, built in 1941 on ground that only exists because the level of Lake Washington was lowered in 1916, and it turns out 737 MAX airliners and P-8 Poseidon military derivatives. A Title V permit is not an accusation; it is a reporting and limits regime, and it means the emissions from these two sites are counted and capped rather than guessed at. It also means Renton's industrial air story is concentrated in a fairly small part of the city, down near the lake and the airport.

Up the Cedar River valley, and the winter burn bans

Nine miles southeast of Renton, out past Maple Valley, is the Cedar Hills Regional Landfill: 920 acres taking roughly 2,500 short tons of waste a day delivered by about 130 trucks. It has a bioenergy plant that captures landfill methane and burns it to make electricity for the Puget Sound Energy grid, and it holds a Title V permit of its own. It sits upvalley of Renton, which matters on nights when cold air drains down the Cedar River valley toward the lake.

The other winter factor is much closer to home. Wood stoves and fireplaces are the main reason the Puget Sound Clean Air Agency calls cold-season burn bans, and Renton is in King County, where a Stage 1 ban is issued when the 24-hour average of fine particles is expected to exceed 35 micrograms per cubic meter within 48 hours. That is a later trigger than Snohomish and Pierce counties get, where the agency acts at 30 micrograms within 72 hours. If a ban is called, uncertified stoves and fireplaces stop, and all outdoor burning stops with them.

Renton air quality FAQ

Why is there smoke in Renton today?

It depends on the time of year. In July, August and September it is usually wildfire smoke that has traveled in from fires well outside King County, and it arrives across the whole region at once rather than in one neighborhood. From late autumn through winter, smoke you can actually smell in Renton is far more likely to be wood smoke from stoves and fireplaces nearby, held down by a cold, still night. If it is neither season and the haze is local to the valley floor, traffic on I-405 and SR 167 is the more likely source, and it clears when the wind picks up.

What is the air quality in Renton right now?

The map on this page reads live PM2.5 from PurpleAir sensors around Renton rather than one official number for all of King County, which matters in a city split between a valley floor and a plateau. Coverage here is good, with dozens of outdoor sensors reporting inside the city and its immediate neighbors, so you can usually find one within a mile of where you actually are. Canairy turns whatever that sensor is reading into a plain-English verdict and can alert you when it crosses a level you choose.

Does the Boeing plant affect Renton's air?

The Boeing Renton factory is a major source under the federal Title V program, which is why the Puget Sound Clean Air Agency issues it an air operating permit and tracks what it emits. Kenworth Truck Company in Renton holds one too. That regime sets limits and requires reporting rather than leaving emissions unmeasured. For day-to-day air on the ground, most Renton residents will see more variation from traffic and from winter wood smoke than from the plant itself, and the sensor nearest you is the honest way to tell.

When does Renton get a wood-burning burn ban?

Renton is in King County, so the Puget Sound Clean Air Agency issues a Stage 1 burn ban when it expects the 24-hour average of fine particles to exceed 35 micrograms per cubic meter within 48 hours. Stage 1 stops burning in fireplaces, uncertified wood stoves and uncertified inserts, and stops all outdoor burning including recreational fires. Stage 2 goes further and stops any wood burning at all, certified stoves and pellet stoves included, unless you have an approved sole-heat-source exemption. Under both stages, visible smoke is prohibited even from an exempt device.

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.

Get Canairy free on Google Play.