New recommendations this week from the Centers for Disease Control and Prevention call for everyone, vaccinated or not, to wear a mask in public indoor spaces in areas with substantial or high transmission of covid-19.
As it turns out, that applies to more than 63 percent of U.S. counties - including many of the places travelers are heading this summer.
Of the top 25 destinations this summer for flight bookings on the Hopper app, only two (Detroit and Minneapolis) fell in the "moderate," masks-not-recommended category as of Friday, according to CDC data. Officials recommend masking indoors for the other 23, a list that contains popular cities across the country that are seeing cases rise rapidly as the delta variant spreads.
Just because the CDC says people should wear masks in a certain area doesn't mean there will be a local mask mandate. But some destinations, including Washington, D.C., and Los Angeles County, have already announced indoor mask rules for all. Private companies can also put their own rules in place. All of that means it will be difficult for travelers to know exactly where masks will be required - especially as rules fluctuate.
Driving the CDC's recommendations is the transmissibility of the delta variant, which vaccinated people can spread in the case of a breakthrough infection, even if they are asymptomatic or only mildly ill. The CDC's covid data tracking site has county-specific breakdowns that include vaccination rates, coronavirus case numbers, hospitalizations, deaths and the level of community transmission.
Keith Armitage, an infectious-disease expert and medical director of the University Hospitals Roe Green Center for Travel Medicine and Global Health, said in an email that the variant's risk is low for a fully vaccinated traveler without underlying health conditions. Travelers should therefore consider any conditions they might have that raises their own risk, the risk of transmitting the virus to someone else and the level of community transmission wherever they're going.
"Masking reduces the risk," Armitage said. "The risk is greatest indoors, and to try to damp down transmission while there is an effort to get more folks vaccinated masking indoors can reduce, but not eliminate transmission. So travelers may need to adjust their activities to avoid being unmasked indoors."
At the moment, according to the CDC, these 14 U.S. destinations require extra caution.
- Las Vegas
The CDC recommends masks indoors in Sin City, where transmission is high - and the state requires them. Nevada Gov. Steve Sisolak, D, said Wednesday that people in counties with substantial or high transmission, including Clark County, where Las Vegas is located, would be required to wear face coverings in public indoor areas. The rule went into effect Friday.
- Orlando, Fla.
Orlando and the surrounding region are home to some of the world's largest theme parks, including Walt Disney World and Universal Studios. The area is also the site of high levels of community transmission, according to the CDC, which means masks are recommended indoors.
Disney has already changed its rules, as of Friday, to require all guests to cover their faces indoors. And while there are no statewide mask mandates, the mayor of Orange County - which includes Orlando - declared a local state of emergency this week requiring masks in county buildings and urged residents and tourists to mask up indoors.
But it's not just Orlando: The CDC recommends indoor masking at every tourism destination in Florida, including Miami, Fort Lauderdale and Tampa, which are also among Hopper's most-booked summer getaways.
- Los Angeles
Los Angeles County was ahead of the CDC's updated guidance when officials reintroduced an indoor mask mandate, even for vaccinated people, earlier this month. The CDC says transmission is high in the county, which is home to around 10 million residents.
Mayor Keisha Lance Bottoms, D, issued an executive order Wednesday that requires everyone, vaccinated or not, to wear a face covering in public places indoors. According to the CDC, coronavirus transmission is high in Fulton County, which includes Atlanta.
With substantial levels of covid spread, Denver also falls under the CDC's updated mask recommendations. The Denver Post reported Tuesday, however, that authorities there had no plan at the time to mandate mask-wearing.
Cook County, which includes Chicago, now has substantial levels of coronavirus spread, according to the CDC. The county and city have both suggested that updated mask rules could come soon, the Chicago Sun-Times reported.
Because of a substantial level of community transmission, people in King County - where Seattle is located - should wear a mask in public indoor spaces, the CDC says.
- Phoenix, Ariz.
Transmission is high in Maricopa County, according to CDC data, meaning anyone in Phoenix, Mesa and their surrounding areas should mask up indoors. On Wednesday, Phoenix said rules around face coverings and physical distancing would be reinstituted for city buildings, effective this upcoming Monday. Private businesses can set their own rules around masks, the city said.
Transmission is high in Dallas County, according to the CDC, as well as in the counties that include Houston and Austin, which are also top summer destinations. While the federal agency recommends masks in those areas, Texas Gov. Greg Abbott, R, issued an executive order after the updated guidance to keep local governments from putting mask mandates into place.
- New Orleans
Transmission in Orleans Parish - along with every other part of Louisiana - is high, the CDC says. New Orleans requires masks in some places, such as city government buildings and hospitals, under guidelines updated July 23. In other locations where people from different households would gather, the city has an indoor mask "advisory" for both unvaccinated and vaccinated people.
- New York City
With substantial levels of transmission, New York City falls into the "everyone should mask" category under the CDC's new guidelines. Mayor Bill de Blasio, D, said the city would provide new guidance on mask-wearing Monday, according to the New York Daily News.
The CDC reports high transmission in Davidson County, which includes Music City. But Nashville Mayor John Cooper, D, said Tuesday, after the new guidelines were announced, that he had no plans to put a countywide mask mandate back into place, the Tennessean reported.
Honolulu is seeing substantial community transmission, the CDC says - but mask rules won't need to change as a result. That's because Hawaii is still requiring everyone, regardless of vaccination status, to wear a face covering indoors.
In an online Q&A this week, Gov. David Ige, D, wrote that mask-wearing is an effective public health measure that officials can take in circumstances where they don't know who is or is not vaccinated. "Some states that rushed to drop their mask mandates have had to reinstate them because of the spike in cases," Ige said. "I don't want to have to step back once we move forward to loosen restrictions."
- San Francisco
Levels of community transmission are high in San Francisco, the CDC says, and the San Francisco Chronicle reported that local leaders are considering an indoor mask mandate for all. For now, San Francisco is urging everyone to wear a mask in indoor public places.