Seattle Had the Worst Air Quality of Any Major City in the World This Weekend

The air quality in Seattle, Washington was bad enough make the city the most polluted in the world on Saturday, amid ongoing wildfires. Out of around 90 major cities, the Pacific Northwest metropolis reached the top of the worst list, according to IQAir’s Air Quality Index (AQI). The Index value for Seattle peaked at 5 p.m. local time at around 190, in the high range of “Unhealthy.”

Note: IQAir tracks air quality globally, using data from its own sensors as well as governmental data from the EPA, UN, and other sources, but is distinct from the EPA’s AirNow ranking, which was also really bad for Seattle on Saturday.

Portland, Oregon wasn’t far behind Seattle this weekend, ranking third in the most polluted list, with only Lahore, Pakistan separating the two U.S. cities. In fact, basically all of the Pacific Northwest—from Northern California, across Idaho, and into British Columbia—has been experiencing poor air quality for days.

Wildfires are burning across the region, and the resulting plumes are prominent enough to be easily traceable from space. Satellite imagery from the National Oceanic and Atmospheric Administration shows smoke from multiple nearby fires blanketing the Puget Sound, Seattle included. Currently, the closest blaze to the city is the Bolt Creek Fire, which started on Saturday and is only 2% contained.

Though air quality was particularly bad for Seattle and Portland over the weekend, shifting winds have moved the smoke farther inland for the time being. It’s good news for the cities west of the Cascade mountains but bad news elsewhere.

For instance, Leavenworth, a town of about 2,500 people in central Washington, has an AQI of 362 as of writing, which is well into the “hazardous” range. Particulate pollution of that level means that “everyone should stay indoors and reduce activity levels,” according to EPA guidance.

This is far from the first time that the Pacific Northwest has suffered from pollution related to wildfire smoke. Fires are part of the natural ecological cycles of the region. But in recent years, climate change (and other factors like the logging industry and forest management) have increased the number and severity of those fires. 2020 was a particularly bad fire year for the West, and thus for the resulting air quality.

One study published last month in the journal Nature Communications noted that a new seasonal pattern of air pollution seems to be developing in the Pacific Northwest and nationwide, as smoke easily moves from one region to another. The researchers found that August air quality was worsening across the country, in large part because of smoke from fires burning in the northwest.

Wildfire smoke can be particularly dangerous, dirty, and harmful to human health. Fine particulate pollution is abundant in smoke, and inhaling these tiny particles can lead to both short- and long-term health issues, including difficulty breathing, increased risk of heart failure, reduced lung function, and premature death.

So far, 2022 has been an uneven fire season in the western U.S. June 2022 was a record month, with more acres burning than in any other previous June in 23 years of data, according to NOAA. But things leveled out in July and August, which were less intense. However, now things seem to be picking up steam. Prolonged drought coupled with intense heatwaves in California and elsewhere are creating the perfect storm for more September smoke.

The air quality in Seattle, Washington was bad enough make the city the most polluted in the world on Saturday, amid ongoing wildfires. Out of around 90 major cities, the Pacific Northwest metropolis reached the top of the worst list, according to IQAir’s Air Quality Index (AQI). The Index value for Seattle peaked at 5 p.m. local time at around 190, in the high range of “Unhealthy.”

Note: IQAir tracks air quality globally, using data from its own sensors as well as governmental data from the EPA, UN, and other sources, but is distinct from the EPA’s AirNow ranking, which was also really bad for Seattle on Saturday.

Portland, Oregon wasn’t far behind Seattle this weekend, ranking third in the most polluted list, with only Lahore, Pakistan separating the two U.S. cities. In fact, basically all of the Pacific Northwest—from Northern California, across Idaho, and into British Columbia—has been experiencing poor air quality for days.

Wildfires are burning across the region, and the resulting plumes are prominent enough to be easily traceable from space. Satellite imagery from the National Oceanic and Atmospheric Administration shows smoke from multiple nearby fires blanketing the Puget Sound, Seattle included. Currently, the closest blaze to the city is the Bolt Creek Fire, which started on Saturday and is only 2% contained.

Though air quality was particularly bad for Seattle and Portland over the weekend, shifting winds have moved the smoke farther inland for the time being. It’s good news for the cities west of the Cascade mountains but bad news elsewhere.

For instance, Leavenworth, a town of about 2,500 people in central Washington, has an AQI of 362 as of writing, which is well into the “hazardous” range. Particulate pollution of that level means that “everyone should stay indoors and reduce activity levels,” according to EPA guidance.

This is far from the first time that the Pacific Northwest has suffered from pollution related to wildfire smoke. Fires are part of the natural ecological cycles of the region. But in recent years, climate change (and other factors like the logging industry and forest management) have increased the number and severity of those fires. 2020 was a particularly bad fire year for the West, and thus for the resulting air quality.

One study published last month in the journal Nature Communications noted that a new seasonal pattern of air pollution seems to be developing in the Pacific Northwest and nationwide, as smoke easily moves from one region to another. The researchers found that August air quality was worsening across the country, in large part because of smoke from fires burning in the northwest.

Wildfire smoke can be particularly dangerous, dirty, and harmful to human health. Fine particulate pollution is abundant in smoke, and inhaling these tiny particles can lead to both short- and long-term health issues, including difficulty breathing, increased risk of heart failure, reduced lung function, and premature death.

So far, 2022 has been an uneven fire season in the western U.S. June 2022 was a record month, with more acres burning than in any other previous June in 23 years of data, according to NOAA. But things leveled out in July and August, which were less intense. However, now things seem to be picking up steam. Prolonged drought coupled with intense heatwaves in California and elsewhere are creating the perfect storm for more September smoke.