Firefighters eyeing wildfire risk after battling blaze north of Wellington

Firefighters will spend a second night at the scene of a large wildfire that scorched 10 hectares of bush and park land north of Wellington overnight.

The fire started late on Thursday and took all night to get under control due to the hot, dry and windy conditions.

And there are fresh warnings the hot weather is ramping up the fire risk across the country.

Flames and embers leapt into the night sky as gale-force winds pushed the blaze through 10 hectares of vegetation.

Porirua resident Simon Busby saw it start.

"I saw like a flash of light at 11 o'clock last night. Looked off my deck and saw flames going straight up the bank," he said.

That spark, caught on a live camera feed in Mana, is believed to have been caused by a power transformer.

"We're aware of an explosion but we're not sure if it was the cause, or result of fire impingement," said Fire and Emergency Wellington district commander Nick Pyatt.

Dozens of homes on the edge of the valley were at risk with residents told to prepare for evacuation.

"We were here and police came and checked on us in case we needed to be evacuated," said Porirua resident Mick McKenna.

Luckily the wind shifted, but the fire still burned right through the night as crews struggled with the strong winds.

"We can't put it out until something changes, so for us today the wind has dropped which has allowed us to get in there with helicopters," Pyatt said.

Which meant they could finally get it under control.

Fire crews are working around the clock to put the fire out, and they're especially worried about hot spots, because Saturday's forecast is for even stronger winds which could reignite the blaze.

So they're dumping as much water as possible on the site.

"We'll also be getting crews back tonight to work through some of these hotspots as well," Pyatt said.

And it's these warm windy conditions that are pushing the wildfire risk up for many parts of the country.

"I have one eye on the future because it's going to get drier," Pyatt said.

"In situations like this with scrub around houses, what I'd ask is that people are mindful of having that protected area around their houses."

Because as the hot, dry weather continues, more regions - including Wellington - are expected to be placed under tighter fire restrictions.