The most active Atlantic hurricane season in history, in which a record 11 named storms made landfall, has added billions to the October bill for natural catastrophe losses, according to Aon-owned Impact Forecasting.

Hurricane Zeta, a category 2 storm when it landed on the southeastern Louisiana coast on October 28, was the 11th named hurricane of the season, Impact Forecasting says in its monthly catastrophe report.

Insured losses from Zeta are expected to exceed $US1 billion ($1.4 billion).

Hurricane Delta, an earlier storm that also struck Louisiana, made landfall on October 9, bringing with it significant storm surge and incessant rain. Remnants of Delta led to heavy rainfall, flash flooding and tornadoes across Georgia, the Carolinas and the mid-Atlantic.

Overall economic losses from Delta are projected to reach $US4 billion ($5.5 billion), with half the bill to be covered by public and private insurers.

“The month of October and into early November continued what had already been a record-setting pace for the Atlantic hurricane Season,” Impact Forecasting Director and Meteorologist Steve Bowen said.

“With additional US mainland landfalls, the country has set new records for the number of named storm landfalls (12) and hurricanes (six) in years dating to 1851.

“While the scope of impact to human life and property has been significant, the reality is most of the landfalls have generally missed the highest population density areas along the coastline. The season has been very active, but it could have been even more difficult.”

Wildfires continue to burn across the US, with the worst damage reported in California, Colorado and Oregon. The Glass Fire in California has so far produced economic losses of over $US3.75 billion ($5.1 billion).

Impact Forecasting says seasonal direct economic costs from the fires across the three states will exceed $US13 billion ($17.8 billion), with insurers in line to foot more than $US8 billion ($11 billion) of the losses.

In the Oceania region, a severe storm in Brisbane with hailstones measuring up to 14cm led to insured losses of $US219 million ($300 million) from 26,000 claims lodged. The storm was declared a catastrophe by the Insurance Council of Australia.

Click here for the report.