Some 8,000 firefighters battling two-dozen deadly, destructive fires in Northern California faced another round of rapidly deteriorating conditions Thursday with a forecast of low humidity, dry fuel and winds gusts of up to 45 mph — with no hint of rain.

At least 23 people have died and some 3,500 homes and businesses have been destroyed in sweeping wildfires that broke out on Sunday.

Red Flag Warnings, forecasting dangerous fire conditions, were already in effect for much of Northern California, enveloping the Bay Area, and have been extended from Big Sur to the Santa Cruz mountains.

Gov. Jerry Brown has issued emergency declarations for Napa, Sonoma, and Yuba Butte, Lake, Mendocino, Nevada, Orange and Solano counties.

“We have had big fires in the past," Brown said at a news conference Wednesday, alongside the state’s top emergency officials. "This is one of the biggest, most serious, and it’s not over.”