According to Cody Hill, a California energy company executive, it’s the cleanest L.A.’s air has been since at least 1995, though the United States Environmental Protection Agency's data dates back to 1980. The EPA backed this fact up, announcing that L.A. saw its longest stretch of clean air days since at least 1980.
Hill told TMZ that March 2020 might have been “one of the best months at least since the 1940s," when as he explains, "there was huge migration as we ramped up aircraft production in the L.A. basin to fight WW2.”
The stay-at-home directive has shut down most commerce and travel across the state, which has decreased traffic emissions that usually swell during morning and evening rush hours, leading to less pollution and smog. On March 18, L.A.’s rush-hour traffic was moving 71 percent faster than it typically does on a Wednesday afternoon, according to The New York Times.
On Tuesday, according to IQAir, L.A. had an AQI rating of nine, which puts it in the top bracket in terms of air quality. Salt Lake City, Utah and Denver, Colorado were ranked as having the cleanest air in the world on the same day, with an AQI rating of three. Since the numbers change day-to-day, it appears L.A. may have only had the lowest rating on Monday.