The company said that the war in Ukraine, inflation and volatile markets also damped performance during the period.
The net loss of $285 million in the period compares with a profit of $1.3 billion a year earlier. Analysts had expected a loss of $130 million, according to a consensus forecast, and the company had already flagged the burden from the hurricane last week.
"The first nine months of this year were marked by a confluence of events," Chief Executive Christian Mumenthaler said.
Ian, which came ashore in Florida last month, was one of the strongest hurricanes to ever make landfall in the United States, subjecting the region to extreme winds, storm surges and torrential rain.
It cost Swiss Re around $1.3 billion, it said last week.
(Reporting by Tom SimsEditing by Paul Carrel)
