A shed fire in rural Stratford, Taranaki, is being treated as suspicious, after crews arrived just before 2am to find the building well alight.
In Cambridge, a bedroom fire an hour earlier was quickly brought under control. No one was injured.
In Christchurch, two crews tackled a garage fire at a Ranui St address in the suburb of Wigram, just before 11pm.
Fire and Emergency is asking people in Central Otago and Queenstown Lakes to take extra care not to spark unwanted fires.
Otago community risk manager James Knapp said a "spike day" - when the fire danger rises sharply before dropping back again - is predicted.
He said the region's fire risk is already moderate to high, but on Thursday some areas will rise to very high or extreme because of the weather.
Knapp said there has already been one close call on Queenstown Hill this week.
He asked people to be very cautious with all open fires, including activities that can generate sparks such as mowing or welding.
RNZ
