Lines crews from Northpower mobilised to repair a fault south of Ruakaka where 672 customers are currently without power about 9pm yesterday.
The outage follows a large tree taking down lines.
Northpower Network General Manager Graham Dawson said power should be restored to most of the affected customers this evening.
Provided there are no further outages caused by the remnants of Cyclone Lusi - only 100 Northpower customers around Whangarei District will be without power overnight.
Lines crews will complete remaining repairs from shortly after 6am, Sunday morning.