Sacramento area air quality better for 2nd straight day. But will it stay that way?
Air quality has greatly improved Wednesday and Thursday in the Sacramento area, as wind patterns continue to push smoke from California’s wildfires away from the capital.
The air quality index for downtown, rather astonishingly, was measured at 0 for particulate matter pollution (PM 2.5) as of 7:30 a.m. Thursday, according to local air district monitors at SpareTheAir.com and the U.S. Environmental Protection Agency’s AirNow map. Other air pollutants, such as ozone and PM 10, were also minimal.
Zero is the best possible reading (there is no negative AQI), and it marks the second straight day of air quality levels levels across the most of Sacramento and Yolo counties starting the day in the green-shaded “good” range of AQI 0 to 50. The AQI in Woodland was recorded at 1, Elk Grove at 12 and the UC Davis campus at 27 early Thursday, according to Spare The Air.
It’s a stark contrast from pollution levels that spiked above AQI 200 over the weekend and made it very unhealthy to spend any significant amount of time outdoors near the capital.
Now, just a few days later, the air quality is almost ideal — in the immediate Sacramento area and the Bay Area, at least.
AQI levels remain elevated throughout much of Placer, El Dorado, Nevada and Amador counties, the AirNow map shows, including an AQI above 200 (“very unhealthy”) in South Lake Tahoe as of 6 a.m. Thursday.
As record acreage burns statewide, and as Sacramento continues to be surrounded in multiple directions, albeit with distance, from multiple massive wildfires that aren’t fully contained, onshore winds from the Bay Area and a Delta breeze helped clear near-surface smoke away from the middle of the Sacramento Valley, according to the National Weather Service.
Fortunately for Sacramento, the only major blaze burning upwind of the capital city at the moment is the LNU Lightning Complex in the North Bay. That fire complex, burning since Aug. 17, has scorched over 363,000 acres, but it is 98% contained and therefore producing minimal new smoke, according to Cal Fire.
Forecasts for near-surface smoke from the National Weather Service, as well as the AirNow map from the U.S. Environmental Protection Agency, each show air quality is still very poor throughout much of the rest of California. That includes the northern reaches of the state; roughly the southern third of the Central Valley, including Fresno and Bakersfield; and the Sierra Nevada mountains and foothills, including areas just east of Sacramento.
The NWS Sacramento office pointed out Wednesday on social media that even though air quality is much improved, the sky may still look hazy. That’s because the onshore wind is pushing away near-surface smoke, but there’s still “quite a bit of smoke higher in the atmosphere,” the weather service writes.
Spare The Air currently forecasts that most of Sacramento, El Dorado, Yolo and Solano counties will remain in the “moderate” AQI range of 51 to 100 later Thursday and Friday. AQI is also predicted to stay below 150 in Sacramento this weekend.
As Spare The Air warns, though, air quality “can change quickly at different times during the day due to wind shifts and vertical mixing,” and if you can smell smoke, you should avoid outdoor activities.
This story was originally published September 16, 2020 at 6:59 AM with the headline "Sacramento area air quality better for 2nd straight day. But will it stay that way?."
