"The last of the real heavy stuff is on its way out of there."
A spokesman for police said surface flooding may close some roads and make others dangerous to drive on this morning.
Multiple landslips have closed several roads in the Nelson region.
Ms Fleming said a heavy rain warning for the Bay of Plenty had been revised, and showers were expected through areas of the North Island today.
"In Auckland ... there is a band of showers out to the west at the moment, some quite heavy showers. Later on this morning we could get a few showers in Auckland but we're not expecting huge amounts of rain with those," she said.
The weather pattern that saturated the Tasman region yesterday would move over Canterbury and Otago today, but was unlikely to produce as much rain.
"We're expecting rain to continue down there for most of today, looking at 8pm tonight [before it eases]," Ms Fleming said.
MetService meteorologist Daniel Corbett told Radio New Zealand the rain in the Tasman region yesterday was "very heavy, very intense" with up to 30mm in an hour in some areas.
COLD SNAP ON THE WAY
WeatherWatch.co.nz said a "cold snap" later this week would bring "rain with snow to basically sea level for eastern areas of the South Island and low levels about Wellington and the North Island's east coast plus central areas to boot".
"Big southerlies are likely to hammer parts of the Wellington region and also Wairarapa as well, with conditions bleak for many areas across New Zealand."
It said there was potential for significant falls in the Christchurch area.