With several highways severely damaged, Waka Kotahi is urging people to reconsider long weekend plans and to check the latest information on road closures and restrictions before starting their journey.
A number of state highways are closed because of significant slips and other damage, and lengthy detours are in place.
In Auckland, 32 roads remain closed.
An orange rain alert is in place for Bay of Plenty west of about Kawerau - including the Rotorua Lakes District, Western Bay of Plenty District and Tauranga City until 11am Friday.
A further 40 to 50mm of rain is expected to accumulate on top of what has already fallen, with peak intensities of 10 to 15 mm per hour, MetService forecasts.
A heavy rain warning for Westland south of Otira is also in place until 4pm Friday, with a further 150 to 220 mm of rain expected to accumulate about the ranges, and 50 to 80 mm near the coast.
In Tāmaki Makaurau, a heavy rain watch is in force until 11am Friday, but MetService says it's at the lower end of the scale.
There is still a risk of thunderstorms bringing heavy rain in the west tomorrow afternoon and evening, as high humidity hangs over the region.
But MetService says the warm, moisture laden mass that is hanging over the country will start to clear at the weekend and conditions in the North Island should be much drier and cooler by early next week.
Read back on RNZ's blog for Thursday's weather updates:
