Face masks will be required at all outdoor events with 500 or more people in King County starting on Tuesday, Sept. 7.

That includes Seattle Mariners games at T-Mobile Park, Seahawks and Sounders games at Lumen Field and Huskies games at Husky Stadium, according to a King County spokesperson.

As new COVID-19 cases and hospitalizations surge, King County Health Officer Dr. Jeff Duchin issued a local health officer order on Sept. 2 requiring masks at large outdoor events starting next week. This requirement applies to all vaccinated and unvaccinated people, 5 years of age and older.

King County, like much of the nation, is in the midst of a surge in COVID-19 cases driven by the highly contagious delta variant. With high rates of disease transmission, and our health care system straining to keep up, it is time to take additional steps to keep ourselves and our communities safe, according to a news release from County Executive Dow Constantine.

Masks are strongly recommended for everyone 5 years of age and older – both vaccinated and unvaccinated – in any other outdoor setting where people cannot remain at least 6 feet apart from non-household members.

Masks will continue to be required for everyone 5 and older in indoor public settings, such as arenas, grocery stores, malls, gyms and community centers. This requirement supports Washington’s statewide indoor mask mandate.

“King County is committed to putting people first, and today’s order fully recognizes the risk to communities and our health care system if we don’t take action now to further prevent the spread of COVID-19,” Constantine said. “King County has led the country with high vaccination rates and some of the lowest rates of infection in the nation. Our residents have done amazing work to protect one another over the past 18 months, and we need to bring that same focus to battling the delta surge and keeping everyone in our community healthy.”

While King County has some of the highest vaccination rates of any large metro area in the United States, there are still approximately 750,000 people in King County who remain unvaccinated and susceptible to COVID-19, according to the news release. This includes children under 12 who don’t yet have the option of getting vaccinated.

“King County COVID-19 vaccine completion rates vary by age, race, ethnicity and geography,” the order explains. “The completion rate is significantly lower in younger age groups (64% in 12-19 years old, 64% in 20-29 years old; 73% in 30-39 years old populations).”

Approximately 320,000 King County residents who are eligible for vaccination remain unvaccinated. Fully vaccinated people have a high level of protection against serious illness and hospitalization from COVID-19, but can still potentially catch and spread the virus to others.

“We will continue to adapt our response measures to the reality of the evolving COVID-19 outbreak,” Duchin said. “The delta variant is more contagious through the air, causes more severe illness in adults, and we have a high level of community transmission in King County and Washington state. Outdoors is much safer than indoors, but there is risk even outdoors currently when large numbers of people are in close, prolonged contact. Layering multiple prevention strategies, including wearing a well-made and snug-fitting face mask when in crowed outdoor locations, is a necessary precaution at this time to limit COVID-19 spread and preventable cases, hospitalizations and deaths.”

The latest surge of COVID-19 cases in King County is taking a heavy toll on hospitals and the health care system. Hospitals are more crowded than at any point since the pandemic began, and our health care workers are stressed and stretched thin, according to county health officials.

“Every day, large numbers of hospitals are reaching out to the Washington Medical Coordination Center,” said Dr. Steve Mitchell, director of Emergency Services at Harborview Medical Center in Seattle. “In the past few days, nearly 60% of the calls have been COVID related. Capacity and staffing issues in hospitals are widespread and consistent across the state. The most significant impacts in Western Washington are in South King, Thurston and Pierce counties.”

With such high rates of community spread and such a large burden on the health care system, both vaccinated and unvaccinated people need to take extra precautions right now, including wearing masks any time they’re around people from outside their household and cannot maintain at least 6 feet of distance.