Dense smoke from massive wildfires burning in neighboring California created hazardous air quality in the Reno-Tahoe area on Monday, canceling flights and forcing the closure of schools, parks and popular summer beaches.
Government air monitors were recording some of the region's most hazardous conditions in years. Weather forecasters and health officials said little relief is expected in western Nevada through mid-week.
The National Weather Service also issued an air quality alert for parts of northeast Nevada’s Elko County more than 300 miles (482 kilometers) east of the closest California fires.
The Washoe County School District closed all public schools Monday in the district serving 67,000 students in Reno, Sparks and Incline Village at Lake Tahoe.
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District spokeswoman Victoria Campbell said a decision about reopening on Tuesday would be made early in the morning.
“We know this is a hardship for our families, students and staff, but winds are unpredictable and we want to make the very best decision with the information we have available,” the district said in a message sent to students' families.
Several flights were canceled Monday at Reno-Tahoe International Airport. Nevada State Parks closed its land around Lake Tahoe on the California line until Friday, depending on conditions, including at a popular beach at Sand Harbor near Incline Village.
The Food Bank of Northern Nevada also canceled several outdoor food deliveries in Reno and surrounding rural areas through Wednesday.
Smoke blowing from the Dixie and Caldor fires in California has blanketed northern Nevada on and off for weeks, leaving particulate matter in the air and causing ash to rain on cars in some areas.
In Las Vegas, more than 400 miles (644 kilometers) south of Reno, Clark County air quality officials issued a smoke advisory for Tuesday.
More than 13,500 firefighters were working to contain a dozen large California blazes that have destroyed hundreds of homes and forced thousands of people to flee to safety. New concerns were developing at the explosive Caldor Fire southwest of Lake Tahoe, the famed alpine lake surrounded by peaks of the Sierra Nevada and resort communities.
The Washoe County School District delayed start times at K-12 schools due to the smoke last Tuesday to wait for winds to clear the fumes.
Last August and September, the district’s schools were closed six times in four weeks due to smoke.
In an effort to combat the spread of COVID-19, the district installed commercial-grade HVAC systems in its schools last year to help ventilate hallways and classrooms. But it has expressed concerns about juggling wildfire smoke outside and the risk of the coronavirus inside.
On Monday, government air monitors for the region measured high levels of particulate matter with diameters smaller than 2.5 microns, spiking the air quality index to 331. The U.S. Environmental Protection Agency considers measurements above 300 to be emergency conditions hazardous to everyone’s health.
The Washoe County Health District said the air quality index was expected to be “very unhealthy” to "hazardous” at times on Monday, Tuesday and Wednesday in the Reno-Sparks area.
It said it declared a “Stage 3 Emergency Episode” on Monday for the first time in its history because the air quality index had remained above 200 for 24 hours.
The alert means “all residents should stay indoors as much as possible,” the district said.
Although the health district has not taken such action, a Stage 3 episode allows the district control officer to issue a shelter-in-place or evacuation order. It also provides authority for the officer to “curtail operations for specific public, commercial and industrial establishments” which are deemed not necessary for public health and safety “and are contributing to the declared emergency episode.”
Under Stage 4, the highest level, the officer may curtail operations at all such businesses and establishments.
The National Weather Service said significant smoke and air quality impacts will continue across the Sierra from south of Yosemite National Park to north of Susanville, California, and parts of western Nevada at least through Wednesday.
The greatest potential for hazardous levels are in Reno, Carson City, Minden, Lake Tahoe, Susanville and Truckee, California, the service said.
It said there’s potential for some temporary improvements in air quality each late afternoon and early evening for some areas, but shifting winds make it difficult to say exactly where and for how long.
Sam Metz is a corps member for the Associated Press/Report for America Statehouse News Initiative. Report for America is a nonprofit national service program that places journalists in local newsrooms to report on undercovered issues.