Outdoor events are way less risky than indoor events when it comes to COVID. They are still, by far, the safest way to gather as the country continues to see high levels of cases and rising hospitalizations.
But "way less risky" is not "zero risk." There's still a chance of catching COVID even at an outdoor event — especially as the virus continues evolving to become more transmissible and to break through prior immunity from vaccination or earlier cases.
"With the more transmissible variants, it's likely that shorter periods of close contact will result in transmission," says Dr. Preeti Malani, an infectious diseases physician and a professor of medicine at the University of Michigan.
That means activities that once seemed pretty safe are potentially riskier – and that includes outdoor activities.
As Maimuna Majumder, an assistant professor at Harvard Medical School and a computational epidemiologist at Boston Children's Hospital, puts it, "the more transmissible a variant is indoors, the more transmissible it is in outdoor settings, too."
So additional precautions during a surge like the one the U.S. is currently seeing may be in order – particularly if you are vulnerable or are in frequent contact with someone who is, say the experts interviewed for this story.
"People are going to make judgments based on [their] own level of risk and comfort," says Donald Milton, a professor of environmental and occupational health at the University of Maryland School of Public Health.
But, Majumder says, "that transmissibility can be drastically reduced by ensuring that an outdoor event doesn't get too crowded." That means having plenty of room for guests to move around – and making sure they are vaccinated, recently tested and symptom-free is also a very good idea, she says.
With the July 4 weekend upon us and wedding season in full swing, experts answered frequently asked questions about staying safe while gathering outdoors with family and friends.
When should guests get tested?
Majumder helped her friend plan a wedding with about 100 attendees, and they have not heard of any resulting cases of COVID.
First, they made sure everything was outdoors, including events that happen around the wedding – rehearsal dinners, happy hours and so on.
They reminded everyone to be up-to-date on vaccinations and boosters, which can help prevent transmission of the virus.
They also asked guests to stay home if they were feeling any symptoms.
And everyone agreed to take a rapid test right before the event.
Majumder has thrown other events and parties with similar guidelines, and so far, she's not heard of anyone getting sick.
And for those who still think that you aren't contagious if you're not showing symptoms, a required pre-event test could surprise you.
"There have been multiple instances where folks without symptoms have tested positive, so they've stayed home," says Majumder, who asks everyone to get rapid tested within an hour of her events. She also keeps rapid tests on hand in case someone isn't able to test before they arrive.
Getting tested right before the event is key. Rapid tests are pretty good at telling someone whether they are positive and very contagious at that moment. But their status can change within hours, so if you take a rapid test in the morning, you could be contagious by night.
Rapid tests aren't always foolproof – sometimes you have a false negative – but they can be a very helpful layer of protection in addition to other precautions.
There have also been times when people felt a bit off and stayed home from one of Majumder's events, only to test positive a day or two later – which meant they would have been contagious during the party.
And in addition to monitoring symptoms, Malani says, "if you add testing and vaccination to a low risk outdoor setting, the risk of COVID becomes manageable."
Do the old rules of staying safe still apply once the event gets going?
Keeping a distance still helps enormously. Whether you're having a wedding or BBQ, that might mean putting families together at the same table, rather than mixing them in with other guests, and spacing each table a few feet apart.
The "15-minute rule" was developed for contact tracers to reach out to people who may have been exposed to COVID. If you're in close contact with someone for more than 15 minutes, you're likelier to get sick. But it is also possible to catch the virus in passing, especially indoors.
Australian authorities reported a case last summer where someone got sick after walking by an infected person for a few seconds at a shopping mall, according to video footage.
Whether you get sick all depends on several factors: how much virus a person is emitting, what your immunity level is from vaccination or prior infection – and, importantly, how much fresh air is between you.
Where do masks fit in?
When it comes to COVID, the outdoors are great for two main reasons: there's plenty of fresh air outside, and you have more space to keep a distance, Milton says.
But if you're not able to keep a distance in a crowd – at a concert, sporting event or protest, for instance – masking up greatly reduces the risks of getting sick.
That's especially true if people are shouting and yelling, if you're near them for a long period of time and if you don't know their vaccination, test and symptom status.
"If you're close together, you're likely to share air with other people," says Milton.
Two of his colleagues believe they caught COVID outdoors early in the pandemic – one at an outside brunch, and one who was waiting in line to pick up groceries in spring 2020.
"There's always been a risk outdoors," Milton says. "It's much lower [than indoors], but it's not nothing."
The closer you are physically to someone, the higher the risk. If you're close enough, say, to smell on their breath what they chose for dinner, you're close enough to inhale the viral particles on their breath.
There is also the off-chance of air blowing the wrong way.
Just like plumes of smoke, virus-laden exhalations can "travel the distance outdoors," Milton says. That means it's possible to get infected even if you're not right next to someone.
But the chances of getting COVID at a distance outdoors are significantly lower than pretty much any other form of interaction, such as talking closer together or meeting indoors.
"I think the most important thing to remember about the outdoors is that while it's safer, it's not 100% safe," Majumder says. "The more crowded an outdoor space is, the more it begins to mimic an indoor space in terms of our exposure to shared air."
But, she says, "I don't think masks are necessary while outdoors as long as the event isn't too crowded, everyone tested negative, no one is experiencing symptoms and everyone is up-to-date on their vaccinations."
What if we need to go inside during an outdoor event?
Even if your event is outside, people may need to go indoors briefly to use the bathroom or wash their hands — "something I think many folks forget when planning an event," Majumder says.
Guests should wear a high-quality mask, like an N95 or KF94, anytime they need to dash inside. Hosts can keep masks "stocked and accessible" for any of these indoor forays, Majumder says.
"Masks remain very important and very effective," Malani says. Especially if you or a member of your household is high risk, "keep masks handy — not so much for outdoor use, but when you go in and out."
(You can also improve ventilation and filtration indoors by opening doors and windows and running air purifiers in bathrooms or hallways.)
Outdoor tents that don't have side flaps enclosing the space can help protect from the sun or rain while allowing air to pass through. But "if the tent is enclosed, it's not that different than being indoors," Milton says.
And "sometimes, social gatherings end up moving indoors," Malani points out, because of bad weather, high or low temperatures, or annoying mosquitoes — and "that's when transmission risk can go from low to high."
Should I invite people from out of town?
The nature of a big event with lots of out-of-town guests is a recipe for transmission when cases are high. Guests are likely to fly in, stay in hotels that may not have good ventilation, eat inside restaurants and meet up with family and friends. Even if the event that you're hosting is itself low-risk, these other activities may not be.
And "the larger the group, the higher the risk," Malani says, because there are more chances of someone having the virus and passing it on.
"Prevention means using a layered approach," she says. Try to take as many precautions as possible — distancing, staying home if you're sick, testing and masks when needed.
When those measures are taken, she says, "being outdoors is a wonderful way to spend time together."
Melody Schreiber (@m_scribe) is a journalist and the editor of What We Didn't Expect: Personal Stories About Premature Birth. Copyright 2022 NPR. To see more, visit https://www.npr.org.