In the Bay of Plenty, two cars crashed in bad weather this afternoon.
Emergency services from Waikato and the Bay of Plenty were called to the crash on State Highway 29 over the Kaimai Range, police said in a statement.
"The weather in the area is not good and police would remind motorists to drive to the conditions."
Police said while traffic was flowing, motorists should expect delays on the route.
Parts of State Highway 1 north of Auckland flooded this morning, prompting a warning for drivers to take care.
The New Zealand Transport Agency said a section of the highway between Warkworth and the Hill St and Sandspit Rd intersection in Wellsford flooded shortly before 9am.
The agency advised motorists to "drive to the conditions" and to also take extra care if crossing the Auckland Harbour Bridge.
WeatherWatch head analyst Philip Duncan said the worst of the rain had eased by mid-morning in Auckland.
However, the region could expect a mix of showers or patchy light rain this afternoon and evening.
Mr Duncan said there could be some isolated heavy showers, but the main rain band had cleared the region and now lay over the Gisborne Ranges.
The Auckland region was also expected to be battered by surging winds this afternoon. Winds of more than 120km/h were possible before easing tonight.
"While it will certainly be blustery in Auckland City, the worst of the winds will actually be around Great Barrier Island and northern Coromandel Peninsula," Mr Duncan said.
"These same gales extend across the Hauraki Gulf to about Waiheke Island, the outer fringe of the belt of severe winds. To the north, these same winds brush Whangaparaoa this afternoon too."
Mr Duncan said the bulk of the severe weather in Auckland today was outside most of the city's main populated areas.
The wet weather is set to continue for parts of the country tomorrow.
WeatherWatch forecaster Aaron Wilkinson said the South Island could expect mostly sunny skies but a few isolated showers were possible in inland parts of mid-Canterbury and eastern Otago.
Drizzle was also expected in Gisborne and Hawkes Bay, but was expected to clear by noon.
"Auckland actually during most of the day is looking fairly dry, because what happens is the Coromandel Peninsula shelters Auckland City when you get easterly winds coming through," Mr Wilkinson said.
Northland, Coromandel and the Bay of Plenty were not expected to be so lucky and could probably bank on showers tomorrow.
On Tuesday, a fair chunk of the North Island was looking good, Mr Wilkinson said, but areas from Coromandel north should expect showers.
For most of the next five days, Northland and Auckland were expected to bear the brunt of wet weather. MetService said heavy falls were possible for Auckland on Wednesday, with strong northeasterlies and gales in exposed places.
But MetService forecasts predicted light to moderate rain to cover most of the country on Thursday afternoon, with Christchurch and inland Otago most likely to escape a dousing.
