Crews will continue monitoring the site of a suspicious fire in Wellington overnight on Thursday that forced 30 people from their homes.
The blaze began about 2am on Thursday and quickly spread to up to 60 hectares of dry scrub in hills above Happy Valley Road near the suburb of Brooklyn and came within 50 metres of nearby houses.
Fire commander Jock Darragh said remnants of the blaze are still shooting up occasional jets of flame late on Thursday. Winds are forecast to gust up to 75km/h and two crews will monitor the site overnight.
Mr Darragh said the fire is being treated as suspicious and investigators will be at the scene on Friday to determine how it started.
At its peak, 13 fire appliances and three helicopters using monsoon buckets fought the fire. No houses were damaged, but those evacuated said the situation was frightening.
Resident Michelle Carlile-Alkhouri said she was woken by a neighbour banging on her door and screaming to her to get out of the house.
Initially told that a neighbour's home was on fire, she saw after leaving her house that a ring of fire was coming over the ridge. She believed the fire came within about 20 metres from a neighbour's house.
Wellington assistant area fire commander Brett Lockyer said there was no choice but to move residents because flying embers could get into guttering or debris such as pine needles and cause property fires.
Many of those who had to leave their homes went to a Civil Defence centre at Owhiro Bay School, about 1km from the site.
Residents were allowed home from about 8am and were advised on precautions. These included dousing outside walls of the house with water and clearing leaves from guttering so floating embers would be less likely to do any damage.
Crews said the risk of the fire was made worse by gorse which contains flammable oils and could reignite after appearing to be extinguished.