Fire and Emergency New Zealand incident commander Steve Kennedy said crews were having to deal with underground tree roots burning at significantly higher temperatures than the surface temperatures of hot spots identified on Friday night - some in excess of 200degC.
"Today's high temperatures and predicted strong northwesterly winds mean our crews will be working in trying conditions to get these deep-seated fires extinguished," he said.
"We also have a crew still working on the forestry skid sites, continuing to pull them apart and extinguish."
Kennedy asked residents to remember that outdoor fires were still banned in Canterbury.
People should also take care with any activity that could start a fire, such as grinding and welding, as well as mowing.
Anyone seeing smoke should call 111 straight away.
