Weather warnings are in place for Fiordland and Westland.
Residents have been warned to watch for heavy rain in the ranges of Westland from Franz Josef to Otira during Saturday, where rainfall accumulations may approach warning amounts.
In Waikato, heavy rain is expected in areas near the Kaimai Range but should ease there at about midday today.
Tauranga has been deluged by torrential rain this morning with more than half the average monthly rainfall falling in just a matter of hours.
MetService forecasters are warning flooding is likely in the area after 61mm fell in four hours. Anything greater than 6mm an hour is considered heavy.
"I would imagine there would be flooding but I haven't had any confirmed reports," said MetService meteorologist Peter Little.
"There has been a decent amount of rain. In Tauranga there has been a heap of rain, 61mm in the last four hours which is very heavy rain."
"It looks like the heaviest rain has begun to ease although the warnings for that area remain in force for the moment."
The area is among other parts of the Western Bay of Plenty and the Coromandel Peninsula to have been drenched in the past few days.
A Bay of Plenty street has been closed to vehicles after sudden downpours this morning.
The low section of Maleme St, Greerton, is closed because of the flooding.
A Tauranga City Council communications adviser said there was no access to the transfer station.
The council would advise when the road reopens.
Severe weather warnings were issued last night as heavy rain hit Whitianga and parts of the Coromandel Peninsula, flooding roads and closing schools. They remain in place today.
Waikato Civil Defence said there was still a bit of rain hanging about the top of the peninsula but no reported problems this morning. All roads were open and there were no power outages.
Residents have been warned to expect about 80-120mm of rain until 10am on top of what fell last night.
Since it started raining yesterday, Whitianga has been drenched with 100mm of rain.
Mr Little said the heavy rain was expected to break down later today.
Meanwhile, today in Auckland, those out and about in the city should expect patches of heavy showers around the middle of the day which are expected to ease heading into the weekend. Temperatures will, however, remain at a balmy 24-25 degrees.
In the Waikato, rain is expected in the afternoon but that should also ease heading into the weekend.
In the lower parts of the North Island things are looking a little less wet.
Mr Little said those looking to escape the wet weather should head to Wellington.
After light showers tonight, the weather in the capital is expected to fine up with temperatures hovering around 20degC.
Mr Little said parts of the South Island were expected to be very wet, particularly on the West Coast, and it was likely MetService would be issuing wet weather warnings within the next few hours.
"Certainly Westland and Fiordland look like they are in for a lot of rain from later today and through the weekend. Also the Nelson area could see some rain," Mr Little said.
"Eastern areas are looking better and Blenheim is looking quite good."
