A large number of West Auckland homes have been plunged into darkness tonight after a substation overload as the region braces for more severe weather.

Exact figures on how many properties in Henderson and Swanson had been affected in the latest outage were not available because they were constantly changing as power was restored, a Vector spokesman said.

Westmere resident Greg Bailey said he was halfway through doing his washing when the power went off at his Rawene Ave home about 9pm.

However, Bailey was unfazed by the power cut.

"It's a First World problem. It doesn't worry me. I feel for the people who have been out for three or four days," he said.

Bailey said Vector was doing a "brilliant" job at responding to power cuts and doing the best it could to get people reconnected.

Tonight's mass outage follows sweeping power cuts across Auckland after a ferocious storm with similar force to a Category 2 cyclone battered the region on Tuesday night, cutting electricity to 180,000 homes and businesses.

Vector said the storm caused the worst damage to its network in more than a decade.

As of 5.30pm this evening, around 9000 customers were still without power and Vector said it could be days before all areas were reconnected.

However, Vector said it expected power to be restored to all customers affected by the latest outage tonight.

"Customers who find their power is off while their neighbour's is back on, or who find their power is back on but their hot water is off, will need to contact us to lodge a new outage.

"This can be done through the app, even though it is not accurately displaying outage maps, or through our call centre."

Glen Eden resident Randal Meikle said his home lost power at 6.10pm this evening.

"We were plunged into darkness.

"I had to drive towards the city at 7.15pm and could a large portion of Glen Eden, New Lynn and Green Bay also in darkness."

He was unsure if the power cut was related to the mass Henderson and Swanson outage.