It didn’t take much sunlight Friday for the heat to envelop the Bay Area, kicking off a weekend bake that is expected to cook much of the region and leave the interior portions well done.
In the Bay Area, it seems, nature was encouraging residents to participate in Friday’s special “holiday” — National Nude Day.
Still, most residents stayed fully dressed as the mercury soared. By 4 p.m., Brentwood, in far east Contra Costa County, hit a high of 101 degrees. In Livermore, generally the hottest place in Alameda County, it was 99 degrees at 4 p.m., just barely topping an expected high of 98. Morgan Hill, in the South Bay, hit 93 degrees at 4 p.m., sliding in below a forecast high of 96 degrees.
In contrast, relatively modest temperatures left many of the South Bay’s public spaces, such as the pool at Mayfield Community Center in San Jose, empty in the late morning Friday. But some people congregated at the fountains in downtown San Jose’s Cesar Chavez Plaza to cool down as the temperature crept up to the mid-80s by the afternoon.
Just before 1 p.m. at Sunnyvale’s Seven Seas Park, the fountains and overhead water-dumping buckets were the stars of the show to a handful of small children playing as the sun shone down.
Saturday’s heat will likely feel more oppressive, especially given what was expected to happen when the sun sets, National Weather Service meteorologist Mat Mehle said. Overnight temperatures Friday night and Saturday morning were expected to run 6-8 degrees warmer than normal through the region, meaning upper 50s and lower 60s, he said. In high elevation hills, the overnight lows might stay as high as 70.
“We’re going to have much higher lows overnight,” Mehle said. “And that’s where it can really become a problem with heat.”
An excessive heat warning for the central coast and the far interior East Bay was set to start at 11 a.m. Saturday and run through 11 p.m. Sunday, according to the weather service. The Bay Area Air Quality Management District also extended through Saturday a Spare the Air alert that was in effect for Friday.
The weekend figures to be “extremely dangerous,” according to Brian Ferguson, a spokesperson for the California Governor’s Office of Emergency Services.
Brentwood is expected to hit 109 degrees on Saturday, while Livermore may reach 104. Morgan Hill was expected to top off at 102, and Walnut Creek is likely to hit 100, according to the weather service.
Those temperatures, and the warmer overnight air, can leave people’s bodies unable to recover as quickly if they overheat and figures to leave residents more vulnerable than normal, officials said.
“Extreme heat is a killer,” Ferguson said.
In Contra Costa County, health officials opened cooling centers in Antioch and Brentwood to help residents cope. In Santa Clara County, cooling centers are open in San Jose, Santa Clara, Los Altos, Campbell, Cupertino, Gilroy, Milpitas, Morgan Hill, Palo Alto, Saratoga and Sunnyvale. Alameda County did not list any cooling centers open Friday morning.
The problem figures to be even more profound in areas of the Sacramento Valley and Central Valley, where temperatures are expected to run between 106 and 112 degrees. Tourists visited California’s Death Valley in anticipation of temperatures approaching 130 degrees — which would fall just short of a nearly 100-year-old record set in one of the hottest places on Earth.
The first day of the intense heat started Friday as most days do, with a heavy fog bank along the coast that acted for the region as a bit of a natural air conditioner before the sun rose high in the sky.
The effect lasted throughout the day in some areas and will continue to have some impact on the weekend temperatures, Mehle said.
In San Jose, the temperature Saturday is expected to top out at 88 after not going past 85 on Friday. San Mateo will get no higher than 81 degrees on either day, meteorologists predict. Oakland’s hottest temperature for the weekend is expected to be 78, and San Francisco may not top 70.
Still, even those temperatures could feel warmer than normal, Mehle said.
“Because we’ve been on the cooler side, the burst of heat we’re getting will feel far more intense,” Mehle said. “We had a couple of really hot days in early July, but other than that, we’ve been running almost 5 degrees below normal. So it’ll be a hard adjustment for your body.”
Mehle said overnight lows were expected to be back to normal by Sunday into Monday, and the region will revert next week to the cooler-than-normal weather pattern that it has seen all spring and summer.
Staff writer Austin Turner contributed to this report.