A fire that ripped through a Northland forestry block and destroyed six hectares of mature pine trees is thought to have been deliberately light.

Specialist fire investigators were yesterday returning to the block owned by Ngati Hine Forestry Trust at Ngapipito Rd, Between Kaikohe and Moerewa, to determine what sparked the blaze.

Heavy machinery and a helicopter were on standby as four teams of rural firefighters continued to work through the layers of earth and ash to extinguish hot spots yesterday.

It was expected they would return today.

Advertisement

Two helicopters were used to contain the fire that initially broke out in the 5000 hectare block about 7pm on Sunday.

Specialist fire investigator Gary Beer said the fire was suspicious and police had been notified. Police confirmed they had launched an investigation.

Beer and a specialist rural fire investigator were at the scene yesterday as part of an investigation.

"It's being treated as suspicious and police are involved," he said.

Given the terrain and hot temperatures it was making it tough for those working on the ground.

What caused a fire at Puwera landfill on Saturday about 2.30pm, south of Whangārei, could have been a number of things from a car battery to toxic chemicals.

"There are a raft of items that could have ignited after all it is a load of rubbish," Beer said.

The landfill, 10km south of Whangārei, is jointly run by the Whangārei District Council and Northland Waste.

Advertisement

A contractor dumping rubbish noticed smoke coming from the middle of the pile and raised the alarm. It was initially contained by using helicopters as well as 30 firefighters from Whangārei, Portland, Marsden Pt, Onerahi and Hikurangi brigades. It had smouldered through Sunday but was handed back to the company to deal with.

A ride-on lawnmower sparked a blaze that scorched through about a hectare of grass near Houhora on Monday.

Kaitaia brigade's deputy chief fire officer Ross Beddows said the lawnmower was destroyed by fire. He said fortunately there was no wind but the fire crossed the road but was quickly extinguished.

At one point a farm storage shed was in the line of fire but was stopped by firefighters.

Beddows said conditions were hot and dry.

"You know it's dry when the cow pats are catching on fire."

Meanwhile, WeatherWatch forecasters say most parts of New Zealand will be kicking off February even hotter than January.

It's predicted a heatwave moving back across Australia will affect New Zealand.

"This coming Sunday we'll have a nor'west flow direct from Australia and/or the sub-tropics helping to push temperatures into the 30s for some," head forecaster Philip Duncan said.

The east and north of both islands look to be most impacted by extra heat, while low pressure in the Southern Ocean is helping to fuel windier weather - cooler winds to the south and hotter winds further north.

This coming Sunday expect places like Gisborne, Napier, Hastings, Northland, Waikato and parts of Canterbury, Marlborough and Nelson to all climb into the 30s.