Swiss catastrophe data firm Perils has estimated the Auckland flood catastrophe has so far led to insured losses of about $NZ1.65 billion ($1.5 billion).

Perils says the initial estimates for the January 27 to February 2 event covers the city’s neighbouring regions and are based on loss data collected from the majority of the New Zealand insurance market. An updated estimate of the market loss will be provided in May.

The catastrophe is the first New Zealand insured loss event reported by Perils since it started covering the market in 2019.

“This event is unprecedented being the largest weather-related insurance industry loss historically for New Zealand,” Asia Pacific Head Darryl Pidcock said.

He says the disaster is the third largest catastrophe event for the sector, surpassed only by the Canterbury earthquakes of 2010/11 and the Kaikoura quake in 2016.

Extreme rainfall caused severe inundation across the greater Auckland region and other areas in the North Island, resulting in the costliest weather event for the region’s insurance industry to date.

“The event was fuelled by extraordinarily warm and humid weather throughout the summer which culminated in record-breaking rainstorms… these caused intense pluvial, fluvial and sewage flooding which affected a large number of insured properties,” Perils says.

“The record rainfall amounts were driven by a pronounced atmospheric river which brought moist and warm air masses to New Zealand which collided with strong easterly winds that triggered the heavy convective rainfall over the North Island.

“Although similar rainstorms have occurred in the past, these had previously spared major cities, whereas in this case Auckland was severely impacted.”