"With the wind at the moment, flying conditions are marginal," Fire and Emergency communications adviser Joss Debreceny said.
"Our crews are there and prioritising the response."
John, a caller to Newstalk ZB this afternoon, said it looked to be scrub land, and the wind was strong.
"There's quite a bit of flame. "There's quite a stand of pine trees behind it, but the wind is blowing in the opposite direction at the moment to it."
Members of the public were asked to avoid Governor's Bay Rd, near Cass Bay, as Fire and Emergency responded to the wildfire that is burning gorse near the top of the hill.
"People are urged to remain vigilant and be extremely careful. Avoid any activities that may accidentally cause a fire, including operating machinery, carelessly discarding cigarettes or parking hot vehicles on dry grass," FENZ said.
Firefighters were also battling three smaller fires in the Selwyn District.
A hedge fire was being tackled by six crews on the corner of Old Tai Tapu and Golf Links Rds which started at 1.55pm.
Another was being fought on the side of Clarks Rd, Lincoln, which is believed to be close to a property.
A fire crew was fighting another hedge fire in West Melton on Weedons Ross Rd, which started at 3.12pm, which was believed to be developing into a large blaze with an additional four units called in.