Firefighters in Canterbury battled five separate fires on Monday as temperatures soared.
One of the blazes reached 100 hectares and firefighters were pushed to the limits as heat and high winds fuelled the flames.
On Tuesday, the fires are still burning and principal rural fire officer Bruce Janes says conditions are worse than two of New Zealand's most catastrophic fires.
"We just heard yesterday the fuels are drier and in a worst state than the Port Hills and Pigeon Valley fires," Janes told The AM Show on Tuesday.
The 2017 Port Hills fires burnt through 2075 hectares in 66 days, destroying nine houses and forcing hundreds of residents to evacuate.
The 2019 Pigeon Valley fire in Nelson was the largest fire in modern New Zealand history, burning 2400 hectares and forcing the Nelson-Tasman region to declare a state of emergency.
Janes says the current Canterbury fire conditions are unlike anything he's seen before.
"I haven't seen fire behaviour in New Zealand like this in my career - not with these types of fuels. Manuka is explosive sure but it's never this bad with blackberry willow."
The good news is he says the fires are heading towards being controlled.
"[The fires] behaved pretty well overnight - we've got three cycles of crews on today to keep them contained," he said.
The fires are sizable, meaning firefighters have to stay alert to prevent further spread.
"One's 100 hectares and one's six, and another started five minutes ago behind the Rangiora Racecourse so we've got two aircraft on that one and we'll put it out shortly" said Janes.
He says the blazes are contained, but not yet under control.
When it comes to how the public can help, Janes says fire crews need all the information they can get.
"Any fires dial 111, we don't mind getting hundreds of calls for the same fire - the conditions are so bad we need all that information."