WeatherWatch said the west of the North Island could expect rain today but the risk of thunder and hail was higher south of Taranaki.
Showers with thunderstorms and hail were also possible on the West Coast of the South Island.
Strong wind advisories are also in place for Auckland's harbours, with 25 knot northwesterlies gusting to 35 knots.
Northwesterly gales are expected for exposed parts of Northland, Auckland, Great Barrier Island and the Coromandel Peninsula early Friday morning.
Today's weather
Whangārei
Showers and possible squally thunderstorms. Brisk northwesterlies. High 17C, Low 11C
Auckland
Showers, with possible squally thunderstorms and hail, more likely in the afternoon. Gusty northwesterlies. High 15C, Low 10C
Hamilton
Showers, with squally thunderstorms and hail, more likely in the afternoon. Gusty northwesterlies. High 14C, Low 8C
Tauranga
Periods of rain, chance squally thunderstorms and hail in the afternoon. Gusty northwesterlies. High 15C, Low 9C
New Plymouth
Occasional rain with squally thunderstorms and hail. Gusty northwesterlies. High 14C, Low 6C
Napier
High cloud. Gusty northwesterlies. High 18C, Low 8C
Whanganui
Early morning rain then showers. Gusty northwesterlies. High 15C, Low 7C
Wellington
Early morning rain then a few showers. Strong northwesterlies. High 13C, Low 9C
Nelson
Mainly fine, just a chance of a shower. Northerly breezes. High 13C, Low 4C
Christchurch
Fine with some high cloud. Northerlies. High 15C, Low 1C
Dunedin
Rain clearing early morning then fine with high cloud. Northerlies, dying out evening. High 12C, Low 4C