Insured losses from Typhoon Faxai, which hit Japan in early September, are estimated at $US5-9 billion ($7-13 billion), risk modelling firm RMS says.

“Typhoon Faxai was one of the strongest landfalling typhoons on record in the Kanto region, and the strongest landfalling typhoon in this region to impact the Greater Tokyo area since Typhoon Ma-on in 2004,” Senior Manager Margaret Joseph said.

The estimate includes additional impacts from an increase in materials and labour costs due to the 2020 Olympic Games and business interruption from extended power outages and vehicle losses.

The typhoon was the equivalent of a category 2 hurricane when it hit the coastline, bringing heavy rain and a storm surge and leaving 900,000 people without power on the main island of Honshu.

RMS says wind speeds weakened immediately prior to landfall, but changing characteristics meant a wider area was affected by the storm.