Fire and Emergency New Zealand said five helicopters were being used to battle the blaze, which had been burning since Thursday night in a forestry block north of Waipara.
Firefighters had managed to contain the fire, which has burnt through more than 100 hectares, on Sunday morning before the winds picked up.
“High gusty winds have caused multiple break-out fires this afternoon,” Fire and Emergency said in a statement.
“The fire has jumped the containment line and is now not contained and not controlled.
“We are putting all our resources into bringing the fire under control, including five helicopters responding.”
Earlier this year, a 300ha vegetation fire in the Waikari Valley forced the evacuation of properties in Waipara.
Fire and Emergency asked people not to light outdoor fires and for anyone who had lit one recently to ensure it was fully extinguished.