Fires like the huge one burning in the Port Hills are rare in New Zealand but are likely to become more common, a rural fire expert says.
Officials have confirmed 11 houses have been destroyed after two main fires merged into one large blaze spreading across 2000 hectares.
Dr Tara Strand, the rural fire team research leader at Scion Research, said the behaviour of the fire - which included how fast the fire was moving, the height of the flames, erratic spotting, and flare-ups - was what experts would call "extreme fire".
"New Zealand has had large fires like this one before," Dr Strand said.
"However, this fire is unique in that it is so close to a large population. Impact is huge within the affected communities and the wider city."
Climate change would contribute to heightened fire risk in the future, similar to the size and scale of the Port Hills blaze, she said.
"The combination of climate, vegetation change and people ... [means] we are likely to see this type of fire behaviour increase throughout the drier parts of New Zealand."
New Zealand's maritime enviroment had "buffered" the country from extreme fire seen in other continents such as Australia and America, Dr Strand said.
But extreme fire would increase here if the climate trend continued.
There were still ways people could protect themselves, she said.
"Make sure you cut back vegetation away from your home, keep the grass short, water the yard if you can. Work with your community to develop defensible spaces - green space, fire breaks."