S.F. simmers again in a fall heat wave
Scientists see warming trend in unusual spell
The calendar may say autumn, but that sweat running down your neck says summer.
While it’s common for the Bay Area to enjoy balmy weather in September and October, when the summer fog lifts and the sun finally emerges, a string of near-90-degree days in San Francisco is not the norm.
This week’s scorcher, which follows a warm spell three weeks ago that pushed temperatures in the city to an unprecedented 106 degrees, puts the month on track to be the hottest September ever recorded in some spots across the region.
And in many places, the unusual heat, which climate scientists chalk up to a longterm warming trend, is triggering unusual responses.
On Wednesday morning, even before the mercury hit 80, San Francisco’s Department of Emergency Management texted out a firstever public alert to tens of thousands of mo-
bile phone users warning about the dangers of hot weather.
“San Francisco is not built for heat,” said Rachael Kagan, spokeswoman for the city’s health department. “For someone who is homebound or elderly and doesn’t have access to air conditioning, it can get really hot. If it’s 90 degrees on the street, it can be 95 degrees in someone’s house.”
Meanwhile, city officials opened cooling centers. Stores were selling out of fans, prompting shoppers to turn to spray bottles and inflatable kiddie pools.
The city’s homeless programs chief activated two cooling centers for people in distress, ordered his outreach staff to check on homeless camps and pass out water — and even felt the burn himself as he held a midmorning news conference at City Hall to push for more shelters.
“There are 4,000 souls out on the streets right now (unsheltered homeless people) who will be suffering too from this heat, and they need our help,” Jeff Kositsky said as he stood sweating in the sun on City Hall’s steps for a press conference with Assemblyman Phil Ting (D-San Francisco) to urge the governor to sign Ting’s bill speeding up approval for shelters in several of the state’s big cities. Everyone on the steps looked like they were roasting, and when the remarks were done, they dashed into City Hall to finish the conference.
“It’s too hot,” Kositsky said to a flurry of nodding heads.
Temperatures at San Francisco International Airport, where the weather has been tracked since 1946, are running ahead of any other September, with a daily average of 69.9 degrees, according to the National Oceanic and Atmospheric Administration.
Downtown, this month’s average is 68.3 degrees, running just behind September 1984, but with a forecast that could still push this year to a toasty new record.
Oakland averaged 68.5 for September, while Santa Rosa, San Jose and Livermore had monthly averages in the low 70s.
The thermometer on Wednesday hit the mid-80s in San Francisco. Gradual cooling is expected to begin Thursday and continue into the weekend.
The September heat follows a summer that was also record hot across much of California. The statewide average temperature for June, July and August was 75.5 degrees, besting the prior high of 74.9 degrees in 2006.
Most of the state’s hottest summers since record-keeping began have been this century. While scientists are loath to attribute any one summer or single month to climate change, they say emissions of heattrapping gases from human activities are clearly driving the trend.
“We’re not waiting for climate change to happen. It’s already happening,” said Dan McEvoy, a climatologist at the Western Regional Climate Center, which is administered by NOAA in Reno. “Scientists have done a pretty good job the past couple of decades projecting the warming we’re seeing, and we don’t see any reason why it’s going to be cooler again.”
While climate change has taken many forms, from helping fuel more intense storms to raising sea levels, higher air temperatures are the clearest impact yet, McEvoy said.
At Cole Hardware in San Francisco’s Cole Valley neighborhood, store managers have had a hard time keeping fans on the shelves. They had to restock their inventory after the heat wave at the start of the month, and they’re again running thin.
“We just got a big shipment ... and lot more styles,” said employee Amber Noriega. “We’re lucky we did.”
Concerned that some shoppers might bring back their fans once temperatures dip back to normal, the store recently adopted a no-returns policy. However, after so many warm days, Noriega thinks most people might want to hang onto their whirling blades.
San Francisco officials were inviting those who couldn’t tolerate the heat to swing by one of the city’s cooling centers, which were just that — cold.
“You should bring a sweater,” said Mindy Linetzky, a spokeswoman for the San Francisco Main Library, where one of the centers had been set up.
The additional benefit of stopping by, Linetzky said, was free entertainment. When the alternative is wilting like a baked flower, books and people-watching take on new appeal.
“If you go to a movie or a bar, it’s going to cost something,” she said. “But the entertainment and culture in the libraries doesn’t.”
And then there was always embracing Mother Nature: going to the beach for some natural air conditioning.
“This is what we wait all summer for, when it finally warms up,” said San Francisco resident Jack Breslin, who couldn't resist the cool ocean breeze at Baker Beach. “But when it gets to (almost) 110 degrees like it did a couple weeks ago, that's another thing.”
Andrea Jacobson, who lives in Kenwood, in Sonoma County, but often works in the city and takes her breaks by the water, said things seem different now. And not in a summer fun kind of way.
“You've got your fires, hurricanes, earthquakes and everything else that they're not telling us about,” she said. “Everything is shifting.” Chronicle staff writer Kevin Fagan
contributed to this report.