The two Christchurch fires have now burned through around 750 hectares of land on the Port Hills and one of them is still out of control.
The Marley's Hill fire has now been contained, however the Early Valley fire is still out-of-control, the city council said in an update.
The Early Valley fire has now spread over the ridgeline above Governors Bay and Allandale, with the risk to life and property at the head of Lyttelton Harbour being assessed.
The council recently reported residents are allowed to return to their homes on Holmes Rd and Holmeswood Rise following evacuations in the area.
More than 100 fire personnel are fighting the blazes, Stephen Hill, emergency management coordinator for the Selywn District Council said.
The weather conditions are not helping the efforts.
"Humidity levels are expected to drop today which will elevate the fire risk," he said.
"A forecast wind change early afternoon is also requiring careful consideration."
Twelve helicopters are working to provide fire suppression, protect structures and support crews on the ground.
Two fixed-wing aeroplanes are laying retardant around important structures to strengthen protection from fire.
Geotech experts have been deployed to assess the rockfall hazard over Governors Bay and Allandale.
Air space has been restricted to allow fire-fighting planes to work in the area.
The council reported officials have said the Sign of the Kiwi building, which is registered as a category one historic place by Heritage New Zealand, is believed to be intact.
The fire has spread close to the top tower at the Christchurch Adventure Park, which is the largest mountain bike park in the Southern Hemisphere and opened last December, and is threatening communications repeaters, the council stated.
The park is closed today as a precaution.
Road closures are:
• Dyers Pass Rd is closed between Hackthorne Rd to Governors Bay Rd. Use the Lyttelton Tunnel or Gebbies Pass as the alternate route
• Summit Rd is closed between Gebbies Pass and Rapaki Track
• Old Tai Tapu Rd is closed between Osterholts Rd and SH75
• Early Valley Rd is closed
• Holmes Rd & Holmeswood Rise is closed.