Forecasters say the high temperatures that moved in Monday should dissipate through the week's end, but state and city fire officials said they still plan to keep an eye on hills and other land covered with dry brush throughout the Bay Area.
That danger was on display Monday, as several brush fires drew quick, strong responses from firefighters in Oakland, Orinda and San Jose. There were no reports of injuries or structural damage in any of the blazes.
Temperatures in some areas including the East Bay soared Monday to the low-90s, but were expected to drop Friday to the low-60s in some areas across the region.
Regardless, fire officials said they'll remain on high alert as fire season gets underway.
"We're seeing an extreme increase in our fire activity all due to the drier-than-normal conditions," said Cal Fire spokesman Daniel Berlant. "Already this year we've responded to a 50 percent (increase) in wildland fires than last year.
"This past weekend we saw a (higher fire threat) in Northern California because of those strong winds, so we increased our staff. The winds are expected to diminish this week, so that coupled with the cooler weather is a positive thing."
Regardless, fire crews planned to keep tabs on potential hot spots and flare ups through Tuesday morning in the Oakland Hills, where a blaze early Monday scorched about 2 acres in Joaquin Miller Park. Investigators were trying to determine the cause of the fire; there was a possibility it started at an illegal campfire.
No homes were damaged and no injuries were reported in the fire, which began just after 1:45 a.m. near a park trail. The blaze was under control by 4:30 a.m., according to Battalion Chief Lisa Baker.
In Contra Costa County, heavy smoke was visible about 2 p.m. Monday as firefighters battled a three-alarm grass fire that threatened homes on Ivy Drive and Donald Drive. The fire burned about 10 acres before it was brought under control around 3 p.m.
"A hot day allows the fire to get going, and we're fortunate the winds weren't strong and the humidity was up," said Moraga-Orinda fire Chief Randall Bradley. "That combination helps a lot.
"It's going to be a long fire season, and it's starting early this year."
The San Jose Fire Department quickly doused a small grass fire in Guadalupe River Park late Monday morning before it could spread to nearby dry brush.
Forecasters say residents can expect cooler weather starting Tuesday accompanied by partly cloudy skies throughout the rest of the week.
"A return of the sea breeze will cause lower temperatures," said Meteorologist Diana Henderson with the National Weather Service. "We'll get more of an onshore flow starting on Tuesday because air is coming off the ocean inland."
North Bay temperatures are expected to drop to the low- to mid-70s by the weekend and San Francisco, Oakland and Fremont can expect temperatures to dwindle to the low- to mid-60s.
San Jose and Concord should see a drop to the low-70s by Friday.
Bay City News Service and staff writers Rick Hurd and Erin Ivie contributed to this report. Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund.