With temperatures hitting 30C in parts of the country this week, Fire and Emergency New Zealand has urged people to be extra cautious about starting fires - or doing anything that could start them accidentally.
Wildfire manager Tim Mitchell said the high temperatures, combined with low humidity and at times strong westerly winds, were creating ideal conditions for sparks to catch and fires to get out of control.
"We continually monitor the fire risk in all parts of the country, and this summer we're seeing some areas drying out earlier than they normally do," Mitchell said.
"We have already imposed fire restrictions in some areas, and with more hot, dry and windy conditions likely, more fire restrictions are planned to follow this week.
"We're particularly seeing pockets of very high fire risk on the eastern side of both main islands at the moment, but all New Zealanders should be very careful when doing anything that could result in a fire."
The Hauraki Gulf Islands near Auckland moved into a prohibited fire season on Monday, which meant all open-air fires were banned, and Ahuriri-Heretaunga in central Hawke's Bay would begin a prohibited fire season from Wednesday.
"We are definitely seeing hotter, drier weather patterns, with some locations over the last month only receiving 20 to 30 percent of their normal rainfall, creating a far greater risk of fires," Mitchell said.
"We know 97 percent of New Zealand's wildfires are caused by people. These threaten our safety and property, and our environment and wildlife - and they are preventable."
Wairarapa's southern coastal zone, and Otago's Upper Waitaki and Central Otago area went into restricted fire seasons on Monday.
Nelson-Marlborough's Waimea area would be restricted from 8.00am tomorrow morning, and the Bay of Plenty will move into a restricted fire season from 8.00am this Wednesday morning.
A restricted fire season meant anyone who wanted to light an open-air fire would need to obtain a permit first, which could be applied for at checkitsalright.nz.
Fire and Emergency New Zealand said there had been a sharp increase in the number of fast-moving vegetation fires in the Bay of Plenty district.
Bay of Plenty District Manager Jeff Maunder said there had been 69 vegetation fires in the past month, and three of them had caused a significant amount of damage.
Most of them were the result of burn piles growing out of control, after people did not check forecasts or failed to extinguish them properly, he said.
The most destructive fires were a scrub fire at Te Kaha on 13 November, a vegetation fire which got into orchards in Te Puna on 23 November, and a fast-moving slash fire in the Purataru-Rapuke Forest on 27 November.
"This spring has been a particularly dry season for the Bay of Plenty so far, which means heightened fire risk as we head into the beginning of summer," Maunder said.
"We haven't had a lot of rain, and what we have had isn't making much difference to the dry conditions. We still have a lot of warm winds, which is making the vegetation even drier. The forecast for the next couple of weeks looks to be more of the same."
Bay of Plenty had 500,000ha of commercial forestry, and more than one million hectares of Department of Conservation land, mostly surrounded by grasses and scrub which would transfer fires rapidly to forested areas.
"We're calling on everyone to be vigilant with fire or engaging in activities which could create sparks," Maunder said - and that included tourists and visitors to the region.
Sign up for Ngā Pitopito Kōrero, a daily newsletter curated by our editors and delivered straight to your inbox every weekday.