The Bay Area Chill Could Set Record Lows in These Cities. Some Climate Scientists Are Worried

The Bay Area is about to get frigid enough to potentially break more than a century-old low temperature records in some cities. That’s after a series of cold storms encompassed the region this week, dusting the highest peaks in snow.

Early morning temperatures on Friday — the time between 4 a.m. and 7 a.m. when the region is waking up — in San Francisco, Oakland, Napa, Livermore and Santa Rosa could dip within a few degrees of record lows.

The culprit? Clear skies late Thursday evening and Friday morning after a third cold storm originating from the Gulf of Alaska douses the region in rain and snow. The colder air mass from the northcountry and the lack of clouds may allow heat to escape, potentially causing temperatures to drop quickly.

National Weather Service forecasters said they are evaluating whether to issue public alerts for extreme cold over the next 48 hours, with the possibility that the frigid temperatures extend deeper into Friday and linger into Saturday. But climate researchers said the appearance of the cooler vibes so late in winter is a signal of how human-caused climate change is affecting the cold season.

“This is going to be a lot colder than we’ve seen across the board this winter so far,” said Rachael Kennedy, a meteorologist with the National Weather Service’s Bay Area Office. “That may give us a shot at beating some of the record lows if they cool below what we have forecast.”

Cold temperatures will extend around the entire region from the North Bay, the Santa Clara hills, the Bay shoreline around San Francisco, the East Bay and all the way down to the Monterey area.

Kennedy said temperatures in Santa Rosa may drop to around 27 degrees Fahrenheit — the city’s record low of 26 degrees was set in 1913. In downtown San Francisco — where a record low of 38 degrees was set in 1897 — the air could reach 40 degrees. Oakland’s forecast will hover around 37 degrees, with a record low of 36 in 2011. Napa and Livermore both could plummet to 29 degrees, just two digits shy of their record low of 27 degrees in 2018.

“Some of these lows have been the record low for over a hundred years, so that would be kind of impressive if we could see temperatures drop below them,” Kennedy said. “But we’ll have to see how it plays out as we head into Friday morning.”

But to some climate researchers, this cold snap so late in the winter season signalled the local effects of global fossil fuel burning. Shel Winkley, a meteorologist with the nonprofit research group Climate Central, said if anything, this winter has been marked by warm temperatures — mirroring what’s happening across much of the Western U.S.

Winkley’s group recently analyzed 245 major U.S. cities to determine how climate change is altering winter. They found that in 80% of those cities — including San Francisco — winter is getting shorter by about nine days. San Francisco winters are shortening by six days on average.

“We are seeing more warm days during the winter months than we did prior,” Winkley said.

This trend, Winkley noted, also means it can be colder less often. Since 2020, there have been 52 daily temperature records set in San Francisco. Winkley said only one was for a record-low temperature in 2022.

“This showcases how even in a warming world, there’s still cold weather to be had, and there’s something to the idea that climate change makes all extremes more extreme,” Winkley said.

But while the potentially record-setting cold temperatures this week seem drastic in comparison to the recent warm Bay Area weather, Winkley said the cold would have “been a little more regular in decades past in a more stable climate.” But, he notes, we no longer live in a stable climate.

“Even though this is going to be a significant cold snap, and there is the potential that we could see a record, we know that record cold really just is not as prevalent or as common as it should be,” Winkley said.

While the extra cold temperatures and two weeks of rain may be annoying to travelers and commuters, Kennedy said the cold temperatures are a good sign that winter-like conditions haven’t disappeared entirely.

“I know some people said they thought winter was over,” Kennedy said. “But winter is not over. It’s still here. It’s still thriving. And if you like cold weather, which I do, it’s just nice to see those colder temperatures returning.”

But if you hate winter and the cold, Kennedy said this would be the week to wear an extra layer or stay home during the coldest parts of the day.

“It’d be a really good idea to bundle up and check in on anyone who may not have adequate access to heating,” Kennedy said. “Also, remember to make sure your pets are indoors and to protect any plants that are outside.”