WELLINGTON-Off-duty firefighters have been called back to work in New Zealand South Island's Canterbury to fight blazes sparked by the wild weather and more than 30,000 properties were without power overnight.

Christchurch police were warning people not to travel at all around Canterbury because so much debris is flying around and weather and road conditions were so bad, Radio New Zealand reported on Wednesday.

Electricity lines crews are unable to work because conditions are too dangerous and Christchurch Airport has closed.

The spate of fires stretches from North Canterbury to Timaru, started by trees falling on lines, as well as lines arcing. Severe electrical storms were also hitting much of the region.

Lines company Orion said 28,257 customers don't have power. It said the Selwyn district west of Christchurch has been one of the worst affected areas but there are now outages in the city as well.

Another lines company, Mainpower, said at least 2,000 of its customers in North Canterbury had to spend the night with no power and it expected Kaikoura to lose electricity overnight too.

Alpine Energy says about 1,000 of its customers around Waimate, Geraldine and Fairlie in South Canterbury will not have power overnight.

Flights were canceled or diverted at Dunedin Airport on Tuesday afternoon, with chief executive John McCall saying winds across the runways were too strong. Airlines resumed flights during the evening.

The Canterbury Regional Council has issued flood warnings for the Rakaia, Waimakariri, Hurunui and Waiau rivers.

MetService said 300 mm to 400 mm of rain is expected about the Westland ranges and the main divide in the next couple of days.

The Southland Regional Council has activated its flood warning as headwaters of major rivers rose rapidly after a day of heavy rainfall.

MetService is forecasting severe gales for Nelson and inland parts of Marlborough on Wednesday, with gusts of 90 to 100 kilometers an hour in the lower North Island, with winds gusting up to 140 kilometers an hour in Wellington.

Northerly gales of up to 140 kilometers an hour are expected in the capital on Wednesday, a day after power lines and trees were downed, roofs lifted and trucks bowled over in Canterbury.