Rural fire authorities are preparing for any flare-up of the major fire in the Port Hills near Christchurch as weather conditions change.
The fire is under control, but more than 250 firefighters and emergency workers are working to ensure there are no further breakouts or flare-ups from hot spots.
A state of emergency is still in place.
Another cordon was opened today, with residents who lived on Worsleys Road allowed to get through to their homes.
The Rural Fire Authority said with warm weather and a wind change expected this afternoon, there was the potential for the fire to break out again.
It said new hotspots have been found at the Christchurch Adventure Park and a drone would be used tonight to identify any more in the area.
About 80 percent of the fire perimeter area was now considered controlled, it said.
The Worsleys Road cordon blocking access to 51 homes was lifted at 9am.
Sergeant Steve Sibley said about 40 residents have returned home, and most seemed to be in good spirits.
He said contractors were working to restore power to the road and assess damage to peoples' properties.
The fire, which started more than a week ago, burned through more than 2000 hectares and about 450 houses were evacuated.