Past 2 months hottest ever
Several Bay Area cities are breaking daily temperature records as a heat wave scorches the region, after the hottest August and September on record in California.
The average temperature in California in September was 74.2 degrees, the highest recorded since 1895. August hit an average of 79 degrees, also the peak, according to federal data.
Last month was the planet’s hottest September since such temperature measures began in 1880.
Cities across the Bay Area region broke or tied daily records Friday, National Weather Service officials said. Napa tied its daily record of 97 degrees set in 1961, and Richmond reached 95, tying its own 1961 record high. San
Francisco hit 92 degrees, surpassing its 1988 record of 90. Oakland got up to 94, breaking the mark of 90 in 1974.
San Jose’s high of 95 on Friday eclipsed the 91 recorded there in 1961, weather officials said. Redwood City, at 93, also broke a 59yearold record.
Several cities, including Santa Rosa with temperatures in the
mid90s and Richmond in the low 90s, flirted with daily records Thursday, National Weather Service meteorologist Brayden Murdock said.
On Wednesday, Kentfield broke its daily record high of 92, set in 2015, with a temperature of 93. Napa, with a reading of 97, tied its previous record set in 1961.
October has been hotter this year in the Bay Area than the historical average, with the highest increase — 6.3 degrees — in Napa and Oakland, according to the weather service. Meteorologists and scientists say increasingly frequent heat waves reflect the trend of rising temperatures and a changing climate.
“We have strong evidence that heat waves are becoming more severe when they do occur,” Stanford University climate scientist Noah Diffenbaugh said.
Diffenbaugh said the probability of heat waves through much of the world is increasing. Those heat waves are breaking records for both the highest temperatures that a given region experiences at any time of year and records for specific times of the year.
“This part of the year, including into the autumn, has been warming the most statewide historically,” he said of California.
Around the world, last month was the hottest September on record since 1880, with this year on track to be one of the warmest ever, according to new data from the National Oceanic and Atmospheric Administration.
In California, statewide temperatures rose on average every decade from 1896 to 2018, according to a study Diffenbaugh cowrote this year.
September had the highest increase, followed by August, then October.
The study concluded that higher temperatures and drier weather have worsened California’s wildfire season and will probably continue to do so.
So far this year, three heat waves have already seared the Bay Area during wildfire season.
A midAugust wave and the dry lightning storm that accompanied it ignited California’s megafire season. Another around Labor Day worsened fire conditions. The third wave this week did not start any new fires overnight Wednesday into Thursday, but a red flag warning for highfire danger due to high winds and hot, dry weather remained in effect through 8 a. m. Saturday.
For many Northern Californians, several crises are converging, with the heat waves piling onto a pandemic, wildfires and bad air quality this autumn.
Because of the risky weather, Pacific Gas and Electric Co. preemptively shut off power to 40,000 customers in 20 Northern California counties, including all in the Bay Area except San Francisco and Marin, by Thursday.
To top it off, the California Independent System Operator urged residents to conserve power, anticipating demand to strain the system, to avoid a repeat of rolling blackouts.
Many Bay Area residents lack air conditioning, but for those who have it, or rely on fans to stay cool, they may be left in the hot dark if their power is shut off or they comply with power conservation. Some cities, including San Francisco, Cupertino, Milpitas, Mountain View and Santa Clara, are opening cooling centers with strict COVID19 guidelines. Napa County, which pushed 96 degrees in the city of Napa on Thursday, has not yet opened centers because temperatures haven’t reached triple digits and were due to dip down into the 60s overnight, spokeswoman Janet Upton said.
As PG& E power shutoffs collide with the heat wave in the North Bay, the county has focused on reaching out in person to a few hundred residents who use medical devices that depend on electricity to ensure they have backup or other options, such as four PG& Erun centers that provide power.
The heat waves comes as the Glass Fire, the second major blaze this year in the county, nears containment. As of Thursday, the county was still supporting 134 people and 47 animals who either lost homes or still didn’t have power through either evacuation centers, which were not in shutoff areas, or the state’s hotel booking program, Upton said.
“Everything is different in the time of COVID19,” she said. “During the Hennessey Fire ( part of the LNU Complex), we were dealing with a massive wildfire — dangerous, fastmoving, destructive, deadly — the COVID emergency, an excessive heat warning and a ( public safety power shutoff ). At one point, we had four simultaneous disasters concurrently going on.”
Although winds topping 40 mph on Mount St. Helena didn’t cause new blazes Thursday, Upton said the county’s emergency operations center is still on alert.
“You’ve got to hope for the best,” she said, “but hope isn’t a plan.”