California’s worst heat wave comes into the final day of the Labor Day weekend, with temperatures expected to reach 110 degrees in St. Helena and Healdsburg. It has triggered extreme heat warnings
What is behind extreme temperatures? It’s called a heat dome: an atmospheric cover that traps warm air over the western U.S., triggering intense heat. Read more about the science here The Chronicle’s meteorological science team explained.
Our reporters are eager to bring you the latest news from around the Bay Area today, and our meteorologist is on hand to talk about what he’s expecting.
Latest Updates:
Don’t go to Stinson Beach, Marin officials warn
“If you’re not already in Stinson Beach … we recommend you don’t go,” the Marin County Sheriff tweeted Sunday. “There are hours of delays getting into the area and the parking lots and street side parking are all full.” On Sunday, the sheriff’s office said it had issued more than 145 citations in Stinson Beach. Visitors are asked not to block driveways or park in yards and to treat residents with respect.
California lawmakers want to sort out heat waves
On the governor’s desk is AB2238, a bill that would direct the state Environmental Protection Agency to develop a ranking system for heat waves by 2025. Hurricanes, earthquakes and even atmospheric rivers are ranked by their intensity – so why not heat waves? It’s unclear how the current heat wave will be sorted, but officials say its extreme temperatures and long duration make it particularly dangerous. Passed unanimously with bipartisan support.
Parking lots near the Marin beaches and Golden Gate Bridge area are full
Golden Gate National Recreation Area tweeted that parking lots at Stinson Beach in San Francisco, Muir Beach and Rodeo Beach in Marin County are full. “We welcome our visitors to escape the heat and remind them to be patient, seek shade, and not take chances with cool ocean currents or coastal bluffs,” the park service tweeted.
Dozens of beachgoers flocked to Bay Area beaches Saturday afternoon as temperatures began to warm ahead of an expected heat wave that has state officials worried about heat-related illnesses and possible wildfires.
Greg Griffin/The Chronicle
Even San Francisco is already experiencing ‘extreme’ heat
Heat in San Francisco is considered extreme when it exceeds 85 degrees — and just before noon, the downtown reading was already at 89 degrees. However, it is cooler than most of the city and state.
California grid boss says Tuesday demand will be at an all-time high
Amid extreme temperatures across California, the state’s power grid operator is forecasting the highest power demand in the state’s history. Californians burned 50,270 megawatts of electricity on July 24, 2006, but California Independent System Operator and CEO Elliot Mainzer said at a news conference on Monday that demand expected to exceed Tuesday’s historic peak. He called on Californians to conserve their power during the peak hours of 4 p.m. to 10 p.m. this week, and hoped those cuts and imported power from other states could get the state through Monday and Tuesday without a blackout.
California Grid Issues Emergency Level 1 Notice
In a sign of the severe strain on power supplies caused by the heat wave, the California grid operator issued an Energy Emergency Alert 1 on Monday, the first Level-1 emergency alert for the grid. So far this heat wave, and it’s designed to reduce power demand from large customers and create more supply. If the grid passes Emergency Levels 2 and 3 — which grid officials think will happen on Monday — it’s time to roll out the grid, because demand, sent sky high by air-conditioning use, outstrips supply. Read more about here
Fire danger remains high across California
Officials warn against any activity that could start a fire, as extreme temperatures can further dry out plants and make them more vulnerable to sparks. In most of California.
How long does a heat wave last?
What feels like an endless heat wave will peak this Labor Day, with temperatures of 105-110° F common in areas like the North Bay, East Bay and Sacramento Valley. San Francisco is also getting some heat waves as parts of the city climb into the 80s today. California’s historic heat wave is far from over. As the heat wave is expected to pass, all excessive heat warnings and advisories for the Bay Area and Sacramento Valley have been extended until 8 p.m. Thursday.
Fans take advantage of the shade as they watch the San Francisco Giants play the Philadelphia Phillies at Oracle Park in San Francisco on Sunday.
Scott Straussante/The Chronicle
Mountaineer rescued from Mount Montara suffering from heat exhaustion
According to a tweet from Cal Fire’s CZU branch, authorities rescued a hiker suffering from heat exhaustion on Montara Mountain in San Mateo County on Sunday. Read about here A spate of heat-related deaths over the past year.
A flex warning is in effect from 4pm to 10pm on Monday
During that time, power grid officials are asking Californians to avoid using energy-intensive appliances like dryers or dishwashers and to turn off unnecessary lights. They ask that people keep their air conditioning at 78 degrees or higher during that time (it’s best to cool your home before 4 p.m.). This is the latest in a series of flex warnings during the heatwave.
A biker rides on Lake Merritt during a Labor Day weekend heat wave in Oakland.
Special to Michaela Watseva/The Chronicle
There is a possibility of power cut on Monday
Power grid conditions are expected to worsen on Monday afternoon as air conditioners work overtime and demand for electricity increases. Grid officials anticipate emergency conditions and will ask consumers and businesses to conserve power between 4 and 10 a.m. in an effort to avoid blackouts. Read more about here
What is a heat wave?
Heat waves are defined as unusually hot weather that usually lasts more than two days. But what is considered abnormal varies among distinct geographic regions of California. For example, a high of 95 degrees Fahrenheit might describe a typical summer day in the Central Valley. But these temperatures can be unbearable in San Francisco, where residents live . Meteorologists consider these differences when issuing extreme heat warnings. To read more about go here .
“Total coffee maven. Extreme web geek. Award-winning explorer. Travel aficionado.”