The April storm which cut power to thousands of Auckland homes for days has cost insurers more than $72 million and could put New Zealand on track for the costliest year for weather-related claims.

Figures from the Insurance Council show more than 13,000 claims were made after the storm hit on April 10 and 11.

As hurricane-force winds ripped through the city at up to 140km/h, the storm knocked out power to over 200,000 Auckland properties. Lines company Vector reported that homes were affected for 11 days following the storm.

"The 10 and 11 April storm has been the most expensive so far this year and has cost more than cyclones Gita and Fehi combined," Insurance Council chief executive Tim Grafton said.

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"It has cost more than cyclones Gita and Fehi combined."

The storm was the fourth storm to hit New Zealand this year and could put the country on track for the most expensive year for weather-related insurance claims.

"Last year was the most expensive year on record for severe weather events with $243m in insured losses.

"This storm brings the total for this year to $173.1m and we are only in May and still have the late-April floods to calculate so it is not hard to imagine this year being another big one," Grafton said.

House and contents claims made up the biggest number and dollar value with 10,713 claims and $34.9m while there were 1810 commercial claims for $34.2m.

Marine claims cost $228,125 while motor claims added up to $2.2m.

The council also says the April storm was the fifth biggest this century.

With more extreme weather events the Insurance Council welcomed yesterday's recommendations from the Climate Change Adaptation Technical Working Group on adapting to climate change in New Zealand.

The working group called upon the Government to start on a national adaptation plan that would define what needs to be done first and who does what, along with a countrywide risk assessment to inform it.

It called for strong leadership on climate change, including a review of policy and legislation and factoring climate impacts into government and council procurement processes.

"Every dollar spent on adaptation now will be more than repaid in future savings," Grafton said.

"The longer we wait to adapt, the more it will cost us and if we fail to adapt altogether it will cost us the most."

Five biggest storms of this century

15-16 February 2004, Lower North Island Storms: $148.3m
3-7 April 2017, Cyclone Debbie: $91.5m
11-12 September 2013, Nationwide Storms: $77.1m
10-12 July 2007, Far North/Auckland:/Coromandel $72.7m
10-11 April 2018, Nationwide storms: $72.1m