Insurance claims from last fall's deadly California wildfires have reached $11.8 billion, making it the most expensive series of wildfires in state history, an official said Wednesday.

The staggering number exceeds the total insurance claims from the top 10 previously most costly wildfires in California.

Until last year, California's most expensive single fire was the 1991 Oakland Hills fire that prompted $2.7 billion in claims in today's dollars, according to data from the Insurance Information Institute.

If treated as one disaster, the combined fires in October and December 2017 "represent one of the most damaging natural catastrophes in California history," Insurance Commissioner Dave Jones said at a news conference in Los Angeles.

For comparison, insured losses from the 1994 Northridge earthquake, the costliest quake to strike the United States, were nearly $26 billion in 2017 dollars, according to data from the insurance institute.

Nearly $1.8 billion of the 2017 insurance claims stem from fires that swept through Southern California in December, a rare winter fire whipped by fierce winds. A fire in Ventura and Santa Barbara counties became the largest by acreage in state history, charring 282,000 acres — larger than the city of San Diego.

The figures for Southern California are likely to grow as more people get through the time-consuming process of filing a claim.

The totals do not include claims related to mudslides that buried homes and vehicles in Montecito when torrential rain fell on hillsides burned in the December fires.

Insurance claims from a series of October fires grew to $10 billion, nearly all of them in Northern California's wine country.

Crews this week finished removing debris from the devastated Coffey Park neighborhood in Santa Rosa, a tidy urban community that was leveled when flames rushed through in the middle of the night.

Jones said the combined firestorms damaged or destroyed 32,000 homes, 4,300 businesses and more than 8,200 vehicles, boats and other equipment. Dozens of people were killed.

The figures do not reflect losses suffered by people who were uninsured or at schools and other public buildings.

Jones said insurers have enough reserves to pay the massive claims. But he said the fires may prompt them to re-evaluate the fire risk and raise premiums — or decline to sell insurance at all — especially for homes near forested areas.