Hundreds of Wellington homes and businesses remain without power as the clean-up continues in the storm-battered region.

Six hundred customers had their power cut in Thursday's ferocious storm, Wellington Electricity said.

"The Wellington area witnessed an extraordinary storm causing significant damage to our electricity network and resulted in 30,000 homes and businesses without power at its peak," the company said.

Some customers in more remote rural areas may not have electricity restored until later this week, it said.


Regional Public Health was warning people without power to be careful with food that had been in freezers but may have started defrosting.

Any food still frozen with ice crystals evident throughout the food, and with packaging that has not been damaged or opened, could be safely refrozen but defrosted food could not be refrozen.

Regional Public Health said food that smelt bad, had a different colour, looked affected or had a slimy texture should be thrown out.

Train commuters into Wellington on the Hutt Valley and Wairarapa lines will face delays this week as a result of significant damage to rail tracks in Petone during the storm, KiwiRail said.

"The track damage means no trains will be able to run between Petone and Wellington until repairs are completed and all train services between Petone and Wellington will need to be bus replaced until further notice," Tranz Metro manager Scott Brooks said.

Hutt Valley Area Inspector Mike Hill has urged commuters to consider carpooling if they decide to travel by car into Wellington City.

In Central Otago, Federated Farmers and the Otago Rural Support Trust have called for volunteers to help about 40 farms which had been cut off, and needed external assistance with snow-raking.

Federated Farmers' adverse events spokeswoman Katie Milne said while the vast majority of farms had coped, the situation at Central Otago farms was serious.


"We understand that many farmers in the most affected areas have been or are planning their own snow-raking operations. However for some of the most heavily affected, there may be a shortage of available hands and a lot of work to get through."

Ms Milne said the snow had presented challenges for farmers.

"It is frankly bitterly cold and hard going where even simple tasks, like opening farm gates, is preceded by having to dig the gates out first.

"Perhaps the big concern is what will happen next. Hard frosts will make it hard for stock to get at both feed and drinking water." said the forecast for the week was wet, but the sun would return to some areas too.

"In the North Island the sou'wester typically drives a few showers into Auckland, coastal Waikato, Taranaki and Wanganui while in the South Island it's the West Coast and Southland - neighbouring regions have a chance of a few spillover showers too," analyst Philip Duncan said.

It was expected to be dry and mostly sunny in Wellington, Christchurch and Dunedin this week, with a chance of a shower Monday in Dunedin and Friday in Wellington, he said.

Mid-Canterbury residents were hoping floodwaters would recede, after the swollen Halswell River did not burst its banks as feared.

There had been widespread flooding in Doyleston, Southbridge, Lincoln and Leeston, where volunteer firefighters had to sand-bag about 50 flood-threatened properties.

Civil Defence authorities in Selwyn issued a potential evacuation warning for Tai Tapu residents on Saturday night, but a Selwyn District Council spokeswoman said nobody had to evacuate their homes in Tai Tapu and only one home in Leeston was evacuated.

The Insurance Council yesterday said claims from the storm were likely exceed those from the floods in Nelson and Bay of Plenty in April, which came to $36 million.

Most claims were expected to come from Wellington.