With another heat wave looming this weekend and in anticipation of stir-crazy Californians flocking to the outdoors for Labor Day, some Bay Area communities are closing down favorite coastal haunts to stem the spread of coronavirus.

All Santa Cruz County and city beaches will be shut part of the weekend and all day Monday, with similar restrictions expected throughout Monterey Bay — meaning no suntanning or beach brews to distract from scorching temperatures. Pebble Beach plans to close its iconic 17-Mile Drive and all Del Monte Forest beaches, while the Monterey City Council ratified an order Tuesday to close all beaches over the weekend. Up in San Mateo County, all Pacifica beaches and lots will likewise be closed.

But beware of the backyard BBQ, experts say. After the state’s surge of cases earlier this summer, including infection clusters linked to Memorial Day and Fourth of July gatherings, epidemiologists worry the beach closures could divert people towards riskier activities like backyard hangouts and indoor gatherings — while keeping Californians stuck in a cycle of back-and-forth shutdowns.

HALF MOON BAY, CA – JULY 3: Bicyclist and pedestrians walk past a “Beach Closed” sign at Half Moon Bay State Park in Half Moon Bay, Calif., on Friday, July 3, 2020. California Gov. Gavin Newsom ordered the parking lots of state beaches to close for the Fourth of July weekend to help prevent the spread of the coronavirus. Half Moon Bay added to the closure by restricting visitors access to the beach. (Jose Carlos Fajardo/Bay Area News Group) 

“The beaches are not the problem,” said Dr. Kirsten Bibbins-Domingo, an epidemiologist with the University of California, San Francisco. “The problem is really enclosed activities, with people who you’ve not had a lot of contact with, doing things where you have to take your masks off.”

The closures come as California’s infections are down by nearly half from their peak, with the daily average of new cases down to just over 5,000 per day, the lowest since late June. Since the beginning of August, the state has slashed its cases by about 40%.

Hospitalizations also have decreased, falling below 4,000 this past weekend for the first time in more than two months — and marking a 46% decline from their peak on July 21. And while California ended August with 3,796 deaths — its deadliest month of the pandemic by far — the seven-day average has fallen to fewer than 110 deaths per day, the lowest in about a month.

All that progress aside, experts are worried about a fresh round of infections this fall, which they predict could stem from any number of scenarios where people get together for parties and extended family hangouts with others not part of their “pod.” New coronavirus cases and the flu are likely to pop up as more parts of the economy reopen, including malls and other businesses across much of the Bay Area, under Gov. Gavin Newsom’s new tiered risk system.

But are beaches a risk? Not so much, experts say.

“We think that a lot of it after Memorial Day and Fourth of July were backyard barbecues — if the family comes up for the long weekend, that’s not a good start,” said Dr. George Rutherford of UCSF.

And they just may be forced to spend more time inside to keep cool in the air conditioning. The National Weather Service issued an excessive heat watch for the Bay Area and Monterey from Friday through Tuesday, forecasting triple-digit temperatures in the South Bay, Santa Cruz Mountains and inland Monterey County, with San Francisco and the North Bay trailing behind in the mid-70s to 80s.

A sign just south of the Newport Beach Pier in Newport Beach lets beach goers know that the beach is closed on Saturday, May 2, 2020, during day two of the temporarily ordered closure of all beaches and state parks in Orange County by California Gov. Gavin Newsom due to the coronavirus pandemic. (Photo by Mark Rightmire, Orange County Register/SCNG) 

For prior holiday weekends, beaches from Pacifica to Monterey closed down parking or otherwise curtailed access to keep hordes of people away. Fewer communities are doing so this time around, while many tourist destinations such as Yosemite National Park and Alcatraz have reopened to limited visitors. Santa Cruz will allow surfers and swimmers to cross the beach, but no hanging out on the sand.

Still, public officials are in a tough position, epidemiologists say: In keeping outdoor spaces open, they risk hundreds of people flooding a small space; in closing them down, they risk inadvertently causing people to gather inside.

Unlike past holiday weekends, state officials have not mandated or encouraged broad beach shutdowns. California Health and Human Services Director Dr. Mark Ghaly said Tuesday that beach closures were up to local officials but added that Californians should prioritize spending time outside for short periods with masks on.

“If the decision because of the beach closure is to bring a small gathering indoors, we know that that is going to create a more risky environment for transmission, and (we) would encourage people as much as possible to bring it outside,” Ghaly said.

That’s not to say that outdoor spaces are risk-free, but the potential for infection is closely linked to social distancing and face coverings: The more people that are crowded together unmasked, the more likely it is for someone to pass along an infection, Rutherford said.

Instead of an all-or-nothing approach, Californians should understand the relative safety of what they’re doing and practice minimizing risk with day-to-day decisions, said UCSF epidemiologist Dr. Peter Chin-Hong — especially as the pandemic drags on.

“It’s the activity, not the setting,” Chin-Hong said. “You can totally be unsafe outdoors, just like how you can have unsafe family gatherings.”