A recent report ranked the air quality of all mid-sized US metros in 2020. Which metro saw the largest decline in air quality from the previous year? Bakersfield, California.

This was due in large part to wildfires that ravaged the area in 2020.

Bakersfield.com further stated that:

The report highlighted the improvement in air quality many U.S. cities experienced during a year defined by business lockdowns and stay-at-home orders. But Bakersfield and other cities throughout the San Joaquin Valley saw air quality dip drastically, the report says.

In 2020, the percentage change in the median air quality index for Bakersfield increased 20.9 percent, according to the report, which was compiled from data released by the U.S. Environmental Protection Agency. An area’s AQI is essentially a “yardstick” that goes from 0 to 500, according to AirNow.gov, an EPA website. The higher the AQI, the greater the potential health concerns.

“As the year 2019 was a relatively less active wildfire season, the comparison between these years will always show a higher median AQI value for the year 2020, which is what the data reflects for the Valley and most of state,” San Joaquin Valley Air Pollution Control District spokeswoman Heather Heinks said in an email to The Californian.

She added that the median air quality index for 2021 ended up closer to the 2019 levels due to the less severe wildfire impacts.

Higher temperatures and less precipitation have led to larger and more frequent wildfires. In 2020, 4.2 million acres burned in California, the worst in the state’s history.