Air quality readings were literally off the charts in parts of Oregon and California Wednesday as the latest fires rage across the west.
The Environmental Protection Agency’s Air Quality Index – or AQI – measures air pollution on a scale of one to 500, with lower numbers indicating healthier air. A reading over 200 is considered “very unhealthy” for humans. Above 300 is considered “Hazardous.”
On Wednesday afternoon, AQI readings along the I-5 corridor in Oregon hit 599 on the EPA’s map for Oregon, and upwards of 700 in some locations on the popular PurpleAir monitoring site. Again, the scale is meant to max out at 500.
The Oregon smoke is the result of a number of wildfires burning in the central part of the state and drifting toward the coast.
It’s a similar story in California, where PurpleAir readings around the town of Willits also maxed out the 500 point scale.
Residents across the San Francisco Bay Area sent KRON 4 images of eerie red skies Wednesday as smoke mixed with a thick marine layer to blot out sunlight. The Bay Area is nearing a full month under a Spare the Air warning issued by local air quality officials to curb further human contributions to poor air quality.
After a series of lightning-fueled fires in August, overtaxed fire crews in the west are just now entering the thick of the traditional fire season.