Cal Fire is shifting into fire season across the Bay Area, including Sonoma, Lake and Napa counties, after an unusually busy spring, the state firefighting agency said Saturday.

"The drought has set the stage for an already busy fire season," said Kelley Gouette, operations chief for Cal Fire's Northern Region.

Cal Fire has responded to 1,108 fires that covered 2,541 acres this year, twice the average both for incidents (500) and acreage (1,325), agency spokeswoman Suzie Blankenship said.

Last year at this time, the agency had dealt with 697 blazes covering 1,793 acres.

On Monday, Cal Fire will transition into fire season in the Bay Area and Sacramento region, including the three North Bay counties as well as Amador, El Dorado, Nevada, Yuba, Placer, Alameda, Contra Costa, Santa Clara, Santa Cruz, San Mateo, Solano, Yolo, Colusa and parts of Stanislaus and San Joaquin counties.

Gouette said the shift into fire season in its northern region is more than a month ahead of schedule.