Air quality to stay moderate amid warmer weekend temperatures

Moderate air quality across the Bay Area this weekend will be accompanied by hotter temperatures, though there may be some fog and slight drizzle to start this morning.

Smoke from wildfires burning fiercely elsewhere in Northern California has grayed the skies intermittently in recent days, but the air quality index of every Bay Area region will remain in the 50s this weekend, according to Spare the Air data.

An air quality index of 51 to 100 indicates moderate and below 50 indicates good. Starting Monday, parts of Alameda County and the Santa Clara Valley will start to see air quality levels on the healthier side of 50, according to the data.

Much of the improvement is the result of winds coming off the ocean and blowing smoky air to the east and away from the Bay Area, a National Weather Service meteorologist said in an interview.

“It’s still pretty dry and warm out there,” meteorologist Brayden Murdock said, “but the marine layer is doing us a lot of favors and the winds aren’t too strong.”

Temperatures this weekend will hover from about the mid-to-upper 80-degree range near Norman Y. Mineta San Jose International Airport, while South San Jose could see afternoons that reach the low 90s. Oakland and San Francisco are due to stay in the milder low-70s range.

More inland cities such as Livermore or Concord are projected to see averages in the 90s and even highs that could reach 100. Similar conditions are expected in pockets of the North

Bay, where Santa Rosa may hover around the mid-80s this weekend, but an inland city like Cloverdale could hit triple-digit temperatures.

“If you’re adjacent to the coast, you’ll probably have a nice, cool weekend compared to some of your friends inland,” Murdock said, adding that the warm weather is not unusual for August.

There are no active heat advisories or red flag warnings for wildfire in the Bay Area this weekend. But the lack of meaningful precipitation in Northern California this summer — and the severe drought that has accompanied it — means people need to stay aware of wildfire potential, Murdock said.

Winds, meanwhile, will remain mostly a breeze today with the strongest gusts reaching about 20 mph near San Francisco International Airport.