Sweltering temperatures scorch Bay Area, gradual cool down expected through Fourth of July weekend

Man, it was a hot one.

The Bay Area’s first summer heat wave arrived just in time for backyard barbaques and fireworks shows this Fourth of July weekend as temperatures soared into the upper-90s and triple digits across much of the region Saturday before an expected cool down ahead of the holiday.

The scorching temperatures were forecast to dip a bit Sunday and cool the rest of the long weekend, with highs by Monday and Tuesday expected in the 80s and low-90s in inland parts of the South Bay and East Bay, in the 70s around the San Francisco Bay and the mid-60s along the coast.

“We’ll continue to see a gradual cool down so that most of our temperatures will get closer to seasonable levels,” said National Weather Service meteorologist Brooke Bingaman.

By Saturday afternoon, temperatures had hit 106 in Livermore, 100 in Santa Rosa, 93 in San Jose, 77 in Oakland and 69 in downtown San Francisco, according to the weather service. The readings were expected to keep ticking up into the afternoon, likely reaching highs for the year.

The sweltering heat is the result of air in the atmosphere seeping toward the ground and squishing out the marine layer that typically cools most of the Bay Area, Bingaman said.

At the Wave Waterpark in Dublin, throngs of swimmers seeking to beat the heat Saturday arrived as the park opened at 11:30 a.m. and temperatures crept toward 100 degrees.

“We’re expecting big crowds today probably, our highest single-day number so far this season,” said Dustin Stene, the park’s recreation supervisor. Stene expected as many as 1,600 visitors Saturday. The park added extra lifeguards and staffing in preparation for the busy weekend.

In San Jose, the warm weather sent people flocking to Marco Polo Italian Ice Cream in the Vietnam Town shopping center. “The business has picked up by about 20%,” a store manager said.

But as families enjoy the weekend sunshine, officials urged caution in the heat.

The weather service issued a heat advisory for most inland parts of the Bay Area through Sunday. People sensitive to heat were encouraged to limit outdoor activities during the day. And everyone should drink plenty of water and be careful drinking alcohol.

Emergency officials warned those venturing outdoors to be wary of surging rivers swollen by frigid runoff from the past winter’s near-record snowpack.

Everyone should “avoid fast-moving bodies of water” that “are proving to be very dangerous this time of year,” said Mariah Bickham, an executive fellow with the California Governor’s Office of Emergency Services, in a video posted on social media.

Newly opened trails, until recently closed by snow, beckoned hikers, who officials warned may get lost or slip on icy spots, and high temperatures raise the risk of heatstroke. On the coast, forecasts for small waves mean swimmers lured by the relative calm could find themselves in dangerous currents, while expected high tides mean tide poolers could get trapped by a fast-rising ocean.

And don’t forget about snakes.

“As it gets warm, the snakes will come out,” Darren Johnson, an assistant fire chief for the Rodeo-Hercules Fire Department in Contra Costa County, told the Bay Area News Group week. “They’re gonna want to get to where it’s warm. Sometimes, that’s cement, sometimes that’s a driveway. Sometimes, it’s where mud has been by a side of a road.”

In Santa Clara County, officials opened cooling centers at local libraries, parks and fairgrounds in San Jose, Santa Clara, Palo Alto, Cupertino, Los Altos, Los Gatos, Milpitas, Gilroy and Saratoga. You can find a list of cooling centers at www.preparescc.org/heatsafety or a list of San Jose’s libraries at www.sjpl.org/locations.

Contra Costa County residents needing an indoor place to cool down can call 211 and ask for a CORE outreach team.

Rick Hurd contributed to this report.