Powerco expects about 100 customers in parts of Taranaki will remain without power overnight and Unison says power might not be restored to all customers in the Taupo district until Friday.
Gale-force winds reaching 120km/h closed schools and roads in Taranaki and shut down flights in and out of New Plymouth on Tuesday.
Powerco network operations manager Phil Marsh says it was too windy in some places on Tuesday for linesmen to climb power poles and restore electricity.
Emergency servces are reporting that high winds have died down in Taupo and New Plymouth and minor surface flooding has receded in areas such as Hawke's Bay.
North of Taupo, State Highway 30 from Whakamaru to Atiamuri is closed with trees across the road.
In Hawke's Bay, state highway 2 from Wairoa to Muriwai, is flooded, but still passable, and drivers are urged to take extra caution.
More heavy rain on the way
MetService is forecasting intense rainfall for Coromandel Peninsula, western Bay of Plenty and Tolaga Bay on Wednesday night.
Fine weather should help dry the country out on Friday and Saturday.