A state of emergency has been declared in Christchurch and the neighbouring area of Selwyn.
More than 130 firefighters have been deployed, along with 14 helicopters and three aircraft brought in from across the South Island.
The fires have destroyed at least 11 homes in the area and residents have been told the fire could change direction and spread to other areas.
"We're really struggling at the moment without the helicopters it's too unsafe at night for those, we are trying to do any structure protection we can but that's got to be balanced between lives", Selwyn Principal Rural Fire Office Douglas Marshall said.
The blaze claimed a life on Tuesday when helicopter pilot David Steven Askin died while fighting the fire.
He said the region had been unusually dry for the past three years and the grass in the hills had turned brown over the summer.
Smoke and ash were being blown across Christchurch. On social media, local residents have begun helping the people evacuated by offering them a place to stay. "And we had to go and tell our kids", she said.
Residents of an outlying suburb of Christchurch were evacuated from their homes from 3am on Wednesday morning as wildfires on Port Hills threatened to engulf them, with further evacuations occurring throughout the day as the fires continued to burn.
A forest fire is threatening Christchurch Adventure park - the southern hemisphere's biggest bike park that has been open less than two months..
Mr Askin was dumping water on the blaze when his helicopter came crashing down, the courageous emergency worker died at the scene.
Askin was a member of the elite Special Air Service and his identity was kept secret when he won the Gallantry Star medal in 2014.
"Corporal Askin was wounded by grenade and rifle fire, yet carried on his mission and rescued guests from the hotel as fire broke out", the Defence Force said in a statement.