About 80 residents in Marlborough's Onamalutu Valley have been given an evacuation briefing this afternoon, as a major fire that has scorched about 500 hectares of land continues to burn.
Fire officials have given the residents an update on the fire and a contingency plan, while firefighters work to contain the blaze.
Radio New Zealand's reporter at the scene of the fire said burned land can be seen at the edges of houses, trees have toppled and firefighters continue to work on hot spots.
National Rural Fire Authority incident controller Rob Hands said about 50 percent of the fire has been contained, and he hopes to make more progress later today.
Mr Hands and other officials this afternoon briefed valley residents, advising them to remove anything that could fuel flames from around their properties as well as preparing a pack should evacuation be necessary.
Police will alert residents if they need to evacuate before gathering at the Onamalutu Domain.
Mr Hands said it was unlikely the fire would spread up the valley, but there is that small potential depending on the weather.
Rural fire force controller in Blenheim, Richie Law, said the fire is nothing like he has ever seen in New Zealand.
"It is heartbreaking, it came very close to a lot of houses yesterday and just the shock of people dealing with the fact their houses were being threatened, it's a sad thing to see."
Mr Law said staff yesterday worked about 15 hours without stopping trying to contain the fire.
The weather earlier today provided a window of opportunity to make progress battling the fire which started on Wednesday night and has burned pine plantations, and threatened several houses.
Crews from throughout the South Island and 12 aircraft were deployed today.
The National Rural Fire Authority said the blaze started on forestry land, owned by Nelson Forest Limited.
It said investigators would begin looking for what started the fire.
A farmer living near the fire, Linda Ryan, was on alert for a wind change that could push it towards her property.
"It could come this way if it flared up again. But we did have rain, I was up at 1 o'clock this morning and there was a good hour and a half downpour of rain.
"It may not be enough to dampen things off completely, but I would say it help more than not help."
Marlborough chief rural fire officer Richard McNamara said the fire was not fully under control yet, but south easterlies and a light shower this morning had given firefighters the opportunity to make progress.
"Yesterday was like trying to fight a fire in a giant microwave. But nature has thrown us a different landscape this morning.
"The south easterly came in, some light showers, and that is going to provide us an opportunity to secure on the gains we made yesterday around homes and properties. And then give us a chance to put a perimeter around this fire by blacking it out."
He said any change of weather could see the fire flare up again. Mr McNamara praised the efforts of the crews.
"We had crowning fires, fires leaping from top to tops of trees. It's some of the most extreme fire behaviour that I have seen and I have fought fires here in Australia and in the US.
"So this was a serious fire. It had serious potential to affect communities, affect families and people."
Mr McNamara said the fire was one of the worst he had seen in his career.
"One thing we have done is kept people safe. And we have kept the loss of houses down to zero.
"Which is a huge win for us, given the fire behaviour that was encountered during the day. It was just something that we could just not contain."
Marlborough resident Ted Maher left his home yesterday morning after waking up to the smell of smoke, but said he was not too worried about his house.
"I've seen this many times before. Ever since I was going to primary school, big fires went across these valleys.
"It was worse then without the grate, because it just ran over both sides of the main road and just took everything in its path."
Mr Maher said the fire has not been that easy on his wife, who had just had a hip operation, but she was coping.
Animals to be rescued
The Marlborough SPCA today worked on removing more animals from the area ravaged by fire.
Manager Kaycee Polkinghome said SPCA staff rescued dogs, sheep and horses yesterday, after some animals were left behind by families who had evacuated.
"They've taken what they can. And there's still cats up there for example that owners haven't been able to find.
"So we have had a quick look, can't locate them. So hopefully they will get out."
Ms Polkinghome said some cattle were also moved by owners, but have no water or grass, so the SCPA would relocate them.
She said the nearby SPCA centre had also been evacuated.
'Worst fire season in a decade'
The Rural National Fire Authority said it was in the middle of its worst fire season for a decade, but hoped to use what was learnt in the field to combat future fires.
Operations manager Gary Lockyer said the authority was looking at its fire-risk reduction strategy.
He said it would be looking at the messages it was delivering, and whether they were targeting the right people and areas.
"Out of this year we will definitely go back and get some analysis, and say well, are we getting the right messages in the right areas.
"Because it is different year by year, some of the causes do vary in terms of, it's human cause, but when you drill down a bit further sometimes there can be different reasons for that so it's not always consistent."
Mr Lockyer said the fires that have raged in the past few weeks were fed by the hot weather, extreme wind events and drier-than-expected vegetation.
Oxford fire extinguished
A fire near the Canterbury town of Oxford has now been put out.
Fire crews have left the scene after flames, fanned by strong winds, tore through 60 hectares of scrub yesterday.