Fire and Emergency New Zealand (Fenz) community risk manager James Knapp said that while New Zealand generally had an oceanic climate which kept it fairly moist and cool, there were exceptions such as Central Otago, which had more of a Mediterranean climate.
Coupled with increasing temperatures because of climate change and fuel changes, such as the spread of wilding pines, it was not inconceivable the region could be the scene of "essentially uncontrollable" fires like those experienced in California and the drier parts of the Mediterranean, Mr Knapp said.
Last year, a huge fire on the Greek island of Evia burned for almost two weeks.
The Dixie fire in California burned from July to October and was the most expensive wildfire in United States history.
"If everybody's doing their little bit, then hopefully we can avoid those conflagrations that you've got overseas," Mr Knapp said.
"It’s hard for us to imagine here, but it’s definitely not impossible [they would occur]."
The Pigeon Valley, Ohau and Port Hills fires had all been big, but were nothing compared with the scale of the fires seen in North America, Australia and Europe in recent years, he said.
Recent research from Crown research institute Scion had found the conditions which led to the devastating "Black Summer" bushfire season in Australia in the summer of 2019-20 had already happened at times in Central Otago, and might occur much more frequently with climate change.
"I don't want to make people frightened, but I do want to paint a realistic picture about what they can expect in the future," Mr Knapp said.
Fenz was still working on completing its seasonal outlook in conjunction with the National Institute of Water and Atmospheric Research, and it was too soon to say if the risk this summer would be more than other years.
However, several fires had already got out of control unexpectedly and there was a reoccurring trend of hotter temperatures each year, Mr Knapp said.
Wildfires were not inevitable, and the overwhelming majority in New Zealand were caused by human activity or infrastructure.
Now was the last chance for landowners to spring clean, and it was important to remove debris and create a good defendable zone around property.
People who are using fire for land management should have burn plans, with a plan B that was properly resourced and was more than just calling 111, because firefighters could be busy somewhere else, Mr Knapp said.
It was also important to keep an eye on the weather and how it might change.
