It's not yet summer but parts of the central South Island are reaching extreme fire risk levels.
With parts of New Zealand becoming tinder dry much earlier than usual, a Fire and Emergency spokesperson says fire-stricken parts of Australia show what could happen here.
Climate data shows that strong, hot winds in parts of the country have baked the soil dry already.
NIWA forecaster Ben Noll said the dry weather had happened sooner than normal.
"Especially in the North Island, but also eastern parts of the South Island where it's looking like it will be a very warm end to the spring and a warm start to the summer season."
Areas east of the Southern Alps are tinder dry, much earlier than usual. Fire and Emergency New Zealand said fires already in Otago had put them on alert earlier than usual.
Tasman Sea and New Zealand coastal sea temps are heating up & are now above average for the time of year ️— NIWA Weather (@NiwaWeather) November 26, 2019
Marine heatwave events have impacted NZ's climate during each of the past two summers, so we'll be keeping a close eye on this. pic.twitter.com/FnQgjMOhRv
Mr Noll said gusty westerly winds were to blame. He said there was more to come, and coupled with a forecast lack of decent rain in coming weeks in areas most in need, the fire risk was growing.
"One of those areas is certainly the interior of the South Island and soil moisture levels are drier than normal in interior Canterbury and Otago, but there are a few other hot spots around the country including one in Northland, the Coromandel Peninsula, and a third from Hawke's Bay down to the Wairarapa."
Niwa said the Tasman Sea and New Zealand coastal sea temperatures were heating up and were now above average for this time of year.
It said marine heatwave events had affected New Zealand's climate during each of the past two summers and the organisation would be observing the trend closely.
Isaia Piho, of Fenz in Otago-Southland, said the Tasman fires provided valuable training for many. He said recent scrub fires in his region had prompted earlier planning than usual.
"When it comes to making sure we have the right response capability within the region to manage events ... it's a reality that we cannot change what's happening with the climate - we just have to work smarter with it," Mr Piho said.
Mr Piho said fire-stricken parts of Australia, where six people have died since September and hundreds of homes destroyed, were an indication of what could happen here - on a lesser scale but no less damaging.
"If we've got longer, drier seasons and the vegetation right across our landscape is not as resilient to fire as what it has been then yes, the fire danger could very much be equal to what we are seeing over in Australia."
It comes after last summer brought the country's largest wildfire in more than half a century. The Pigeon Valley fires in Tasman District in February - sparked by a tractor working in a dry stony paddock - burned more than 2000 hectares of commercial plantation forest, property, and pasture.
Fire and Emergency New Zealand (Fenz) has since been advised to develop a nationally consistent framework for tactical fire planning.
It was one of 12 key recommendations of an independent review of the Tasman forest fire response.
Forestry companies in Otago and Tasman have primed their firefighting equipment.
More than half the land burned in the Pigeon Valley fires belonged to Tasman Pine Forests.
Chief operating officer Steve Chandler said they had increased this year's budget for upgrading firefighting equipment, and preparations for the fire season were now well under way.
"We're doing a lot of work in terms of getting our fire ponds within the forest prepared and ready, in terms of making sure they have good access.
"We've also just purchased a new fire engine that will be deployed, and portable fire tanks for the back of our utilities [vehicles]."
Wenita Forest Products head David Cormack said the fire danger was currently moderate, but it could quickly spike due to the hot and windy conditions.
Mr Cormack said all crews were on notice.
"All of our crews go to a pre fire season checklist, making sure that their machines are cleaned down - to make sure there's no debris in any places on the machine that might catch fire," he said.
"They've all been through plenty of fire seasons now, so they know what to do."
Mr Noll said the strong westerlies were forecast to continue for the next month or two.