Most of the country has been soaked over Queen's Birthday weekend but forecasters say more bad weather is yet to come.
An earlier heavy rain watch for Auckland has been upgraded by the MetService to a weather warning, in place from now until 8am tomorrow.
MetService said three weather bands were due to pass south down the North Island through the night.
"One has already passed and is in Waikato, another is passing over Auckland now and another will come overnight."
Between 60mm and 90mm is expected to fall in the region overnight, according to the latest MetService forecast.
It's been a sodden long weekend for Auckland. Some areas have recorded between 40 and 100mm of rainfall so far, with places in the north and east receiving the highest totals.
Auckland Airport recorded just 12mm between 9am and 8.30pm today.
Earlier warnings for Auckland forecast between 60mm and 100mm overnight tonight.
"The rain is what is primarily happening tonight. There are snow and wind watches for tomorrow in the South Island," A MetService spokeswoman said.
Other parts of the North Island including Northland, Coromandel, Bay of Plenty and Gisborne are under watch for heavy rain.
It follows a sodden long weekend for much of the country, with torrential rain sparking flash floods on the East Cape and forcing the evacuation and rescue of families.
Auckland received an average of 60mm of rain fall in the past 60 hours, while Tauranga had 103mm of rain and Waikato 37.4mm.
Katikati recorded the biggest rainfall with 163mm of rain falling in the past 60 hours.
The weather starts improving for Auckland from Tuesday afternoon with most of the bad weather scheduled to the rest of the week expected to flip and hit the South Island, MetService shift meteorologist Claire Flynn.
"From around midday we've got another weather feature coming through and that's going to bring widespread showers, possibly heavy on Wednesday."
Flynn said with this weather cycle the severe weather was going to be down south where snow and strong winds were forecast.
The MetService has issued a heavy snow watch for the 12 hours from 9pm tomorrow for large parts of Otago and Southland and expects significant accumulations above 400m in some areas.
The warning is in place for Fiordland, inland Southland and Clutha, inland Dunedin, Central Otago and Southern Lakes and there is a strong wind watch in place for Coastal Clutha and Dunedin from 7pm tomorrow until 8pm Wednesday.
Auckland, Tauranga and parts of the Coromandel experienced flooding on Sunday, making driving conditions slow for holidaymakers heading back to the main cities today.
Aucklanders have been warned to expect traffic delays this afternoon and through to this evening.
Motorists are also being warned to drive safely with slips, surface flooding and road closures affecting parts the roading network.
Tairawhiti Civil Defence Emergency Management and Gisborne District Council's flood warning team said it would continue to monitor river levels and rainfall in the district overnight.
"Heavy rain bands across the district later this afternoon saw the Hikuwai River north of Tolaga Bay rise abruptly again to 6.4 metres, about four metres above its average flow."
"The Met Service duty manager said the heaviest bands will come over between 6am and midday tomorrow, Tuesday. Periods of heavy rain are expected with possible thunderstorms,"Emergency manager Louise Bennett said.
State Highway 35 is open to traffic after being closed for several hours today.
Up to 30 properties were tonight without power and phones in the area west of Tolaga Bay.
Road contractors are meeting at 5am tomorrow morning to talk through their plans from first light.