The torrential rain has seen homes flooded, roads closed and power cuts - and there is no respite in sight, with the forecast set to remain wet for the weekend.
MetService meteorologist Tom Adams said it was expected rain would keep falling at a rate of 25-40 mm per hour in many places this morning.
"This is a very significant weather event for this time of year and although the rain will ease as the afternoon wears on there is still a chance of localised thunderstorms from Palmerston North northwards," he said.
The rain is expected to ease up across the upper North Island by lunchtime today - but the MetService warns the downpours could be back with a vengeance later this evening and the weather will still be rough over the next 48 hours.
Warnings are still in place for worst-hit areas including Northland, Auckland, the Coromandel and the Bay of Plenty, with localised thunderstorms expected today.
But the weather is not like yesterday when bands of rain swept down the country in waves, so it is hard to predict the timings of the localized storms.
"The really heavy rain we have been having should start to ease in most places from Coromandel to Northland by about noon and into the early part of the afternoon," MetService meteorologist April Clark said.
"But the heavy stuff has the potential to be back in the late afternoon and evening, so we are keeping a thunderstorm watch on for today.
"It will be Monday before we really start to see the worst of the bad weather start to abate," Clark added.
"The weather is not like yesterday when bands of rain swept down the country in waves, so it is hard to predict the timings of the localized storms."
It's been a wild week - Tuesday saw 240mm of rain dumped into the Hunua Falls in the space of 24 hours, causing 350 people to be rescued at two campsites.