Wildfires keeping Northern California air unhealthy. When might the smoke clear?
Light to moderate southwesterly wind in the afternoon on Tuesday and Wednesday is expected to help disperse some of the smoke that has blanketed the Sacramento region over the past several days, as major wildfires have burned hundreds of thousands of acres.
But air quality officials say dense smoke will continue to impact the region through Wednesday with particle levels that will make the air unhealthy to breathe for residents with sensitive health conditions in Sacramento County. In Yolo and Placer counties, the air outside will be unhealthy for anyone to breathe through Wednesday, according to SparetheAir.com, the region’s air quality website.
Placer County officials on Monday afternoon announced that a countywide air quality advisory was extended through Thursday, according to a news release.
“While all people may experience varying degrees of symptoms, the more sensitive individuals — such as young, aged and those with respiratory conditions — are at greatest risk of experiencing serious symptoms,” officials said in the release. “Symptoms may include, but are not limited to, coughing, watery and itchy eyes, headache, scratchy throat, and difficulty in breathing.”
Air quality in California’s capital region was poor and skies were hazy to start Monday morning, as the huge wildfires continued to burn in the northern half of the state.
The Central Valley, the East Bay area and foothills were suffering some of the state’s worst air quality in terms of particulate matter (PM 2.5), the pollutant most closely associated with smoke.
The majority of the valley and roughly west half of the Sierra Nevada foothills had AQI readings in the “unhealthy” range between 151 and 200 as of 7 a.m. Monday, according to the U.S. Environmental Protection Agency’s AirNow live map. That includes virtually all of Sacramento County, the entirety of San Joaquin County, all of Yuba County and the west portions of Amador, Calaveras, El Dorado, Placer, Nevada and Sutter counties.
AQI in the city of Sacramento was 157 early Monday and ranged up to about 170 in other parts of the county, according to AirNow.
Spare The Air predicted an AQI of 169 later Monday, and readings were expected to stay in the unhealthy range Tuesday through Friday. Sunday’s max AQI was 184, according to Spare The Air. At 3 p.m. Monday, downtown Sacramento had an AQI reading of 204; Elk Grove was at 191 and Woodland was at 179.
Air quality officials say that when AQI is above 150, you should limit your outdoor time as much as possible; extended time in the polluted air is hazardous to health.
A storm blowing in from the Pacific Northwest this coming weekend, though it won’t bring rain, could bring cooler air and push some of the smoke out of the Sacramento and San Joaquin valleys, according to the National Weather Service.
The NWS forecasts hazy conditions to continue through most of Tuesday in Sacramento, potentially clearing up visually by Tuesday night absent any major fire flare-ups that produce significant amounts of new smoke.
If you can smell or feel the sting of wildfire smoke from within your home or while driving, there are several relatively simple measures you can take to keep that air outside, such as replacing your air conditioning filter or sealing up any cracks in your walls or windows.
A patch of “very unhealthy” air on Monday was affecting central Plumas County and part of Sierra County, caused by the Claremont Fire burning in Plumas National Forest. Quincy reached an AQI index reading of 280 Monday morning. The U.S. Forest Service reported the Claremont Fire at over 17,000 acres and just 2% containment Sunday evening.
The unhealthy air quality is a result of smoke drifting from wildfires that have burned across Northern California for about a week, after a series of very intense thunderstorms sparked hundreds of minor fires and dozens of major ones via lightning.
The two biggest of those fires — now No. 2 and No. 3 on Cal Fire’s list of the largest fires ever recorded in state history — are the LNU Lightning Complex in the North Bay and the SCU Lightning Complex east of San Jose. Each is about 350,000 acres, or nearly 550 square miles, and grew starting in the middle of last week amid gusty winds that swept them eastward.
Air quality is comparatively healthy to the west of those two fires, in parts of the greater Bay Area and down the coast to Santa Cruz and Monterey, where AQI readings are between 51 and 100, considered moderately unhealthy.
AQI ranged from 101 to 150 (unhealthy for sensitive groups) west of Sacramento through the North Bay, including most of Yolo, Colusa and east Lake, Napa and Solano counties, with the exception of Vacaville, which is suffering air quality about as bad as that of Sacramento, according to AirNow. The bulk of polluted, smokey air from the massive LNU Lightning Complex Fire has blown east of those counties.
Vacaville, where the LNU Fire forced evacautions last week, had an AQI reading of 206 at 3 p.m. Monday and 264 two hours earlier, according to Spare The Air.
Sacramento State University announced in social media posts that the campus is closed due to poor air quality for all nonessential employees, some of whom have not been at the campus anyway due to coronavirus pandemic restrictions. Sacramento State instruction for the fall semester begins on a primarily virtual basis next week.
High temperatures all week are forecast for the mid-to-upper 90s.
Actual recorded temperatures have fallen short of predicted highs in recent days, at least in part due to smoke blocking out sunshine. Last Thursday, most notably, was originally supposed to approach 100 degrees near the capital; instead, it only maxed out at 88, according to the NWS.
This story was originally published August 24, 2020 at 9:29 AM with the headline "Wildfires keeping Northern California air unhealthy. When might the smoke clear?."
