Downpours have hit Northland, Auckland and Coromandel overnight, with Kaikohe seeing 200 millimetres of rain in 24 hours and the Karangahake Gorge closed due to a slip.
Severe weather warnings were earlier issued for many parts of the upper North Island as heavy rain and strong winds battered the country.
They came as parts of Aotearoa remain in clean-up mode following severe weather events earlier this year, such as Cyclone Hale, Cyclone Gabrielle, and Auckland's anniversary weekend floods.
As of 5.30pm, MetService had lifted its warnings for Northland, Auckland and the Coromandel as the front moved south.
Forecaster Gerard Bellam said the storm was moving very slowly, and could linger over the central North Island for most of the week.
Orange heavy rain warnings remained in force for parts of the Bay of Plenty, Gisborne north of Tokomaru Bay, Tasman northwest of Motueka, and Westland south of Otira.
As of 9.30pm, orange heavy rain warnings were issued for Nelson through to Tuesday evening, and for Westland and Fiordland.
Yellow heavy rain watches are also in place for Tongariro National Park, as well as parts of the Bay of Plenty, Buller and Fiordland, and a yellow strong wind watch is in place for Westland, south of Fox Glacier.
Northland received the most rain overnight, with Kaikohe reaching 200 millimetres in the 24 hours to 6am.
In Thames-Coromandel, overnight downpours reached 81mm and more rain is expected throughout the day.
The Karangahake Gorge between Paeroa and Waihi is likely to remain closed for the rest of the day after a slip came down across State Highway Two just after 1pm.
Waka Kotahi said work crews were at the slip near the Crown Hill Bridge to clear the road.
Drivers travelling to the eastern side of Coromandel Peninsula will need to use the Thames Coast Road, SH25.
Those heading to the Bay of Plenty, including Katikati and Tauranga, can use SH29, over the Kaimai Range.
At 6am, Auckland was the wettest place in the country, with 25mm overnight, half of that was since 4am.
Intermittent bursts of rain were occurring in the central city.
As the bad weather moved south, MetService said thunderstorms were expected in the Bay of Plenty.
Fire and Emergency NZ said it had not yet received any weather-related callouts.
MetService said the bad weather was being caused by an "active front associated with a subtropical low" that was moving down the country.
It was "slow moving" and the rest of the week was looking "pretty unsettled", meteorologist John Law said.
Law said the warnings were being extended to Bay of Plenty as the day went on and MetService was "keeping a close eye" on the region on Monday and throughout the week.
The weather was also moving onto the South Island where western parts of Tasman District were expected to "bear the brunt of the rainfall".
"Unfortunately more wet weather is to come." MetService meteorologist John Law
Law told Morning Report it was "really worth" people keeping an eye on the forecast as "unfortunately more wet weather is to come" and warnings could be upgraded or changed.
He said it was likely, as winter arrived, that northern parts of the country which were experiencing heavy rain events might become more settled as warm, moist air coming from the north was lost.
Power restored to parts of Northland
In Northland, dozens of households that spent the night without power have now had their service restored.
Up to 400 properties in the region experienced outages, with 169 households still without power in Waipu earlier this morning due to broken power lines caused by heavy rain.
Northpower Chief Executive Andrew McLeod said crews had worked overnight to repair the lines as quickly as possible.
"We had about 400 customers off for anywhere between two and four hours and as that wind gets up we're just seeing trees get blown across lines again - only a few this time, much lower impact than [Cyclone] Gabrielle, but same sort of impact on the network."
In the Far North, Top Energy said 74 households were still without power, and its teams were working in the field to restore power supply.
Northland Civil Defence spokesman Zachary Woods earlier said the weather was looking a bit more settled this morning but the region had received the majority of the heavy rain.
Listen to the full interview with Northland Civil Defence here
As the day continued, Woods said officials wood be checking if the region had experienced any other major impacts but nothing major had been reported overnight.
Some 111 calls were made but they were dealt with as "business as usual", he told Morning Report.
There had also been some reports of boats coming off their moorings.
'Keeping a close eye'
The Coromandel region appeared to have handled the rain well, its district mayor said earlier, but more would be seen throughout the morning.
Thames-Coromandel District Mayor Len Salt told Morning Report the region was still in recovery mode from earlier severe weather events, including Cyclone Gabrielle.
Salt said 81mm of rain had fallen in the area overnight, but it appeared to have been spread throughout the night, making it more manageable.
Teams had done "a lot" of work to prepare for heavy rain, such as clearing culverts so they could drain properly.
"At the moment, we are not in too bad a shape but nervously watching what is coming down the line," Salt said.
"We seem to have come through OK but we are keeping a close eye on it."
Salt said residents were also being asked to keep an eye on any differences they might notice in the land and to let officials know if they had any concerns.
Residents in the Waikato town of Matatoki were being asked to conserve water for the next two days because heavy rain has caused a sediment build-up.
Thames Coromandel District Council said the water treatment plant was running slower due to the sediment in the stream water is drawn from, and may even be shut off at times.
A water tanker will be at Matatoki School for residents to use.
'Don't take dumb risks'
Thames Valley Civil Defence was warning its resilient residents to stay informed throughout the week and keep away from waterways and beaches when water levels were high and tides were big.
"Don't take any dumb risks," controller Garry Towler said.
"It's not worth the risk."
Towler told Morning Report reports had come through of "huge seas" causing significant coastal erosion. Crews were out investigating.
He said it was of particular concern given the coastal erosion that had occurred during the previous cyclones.
"The roading network appears to have come through OK, as has power" - Thames Valley Civil Defence controller Garry Towler
Rivers were also running "very very high" but the region had got through the night OK.
"The roading network appears to have come through OK, as has power. We appear to be fully intact regarding power supply so that's good news."
However, officials were standing by and keeping an eye on what was lying ahead for the Coromandel this week.
They remained in monitoring mode, he said.
Auckland public transport affected
The weather in Auckland affected ferry services on Sunday, and that continued on Monday.
Auckland Transport said Gulf Harbour ferry services would be replaced with alternative transport because of the weather.
Services affected included the 7.30am, 10.30am and 12.30pm services from Auckland to Gulf Harbour and the 6.30am, 7am, 7.30am, 8.30am, 11.30am and 1.30pm services from Gulf Harbour to Auckland.
All Pine Harbour ferry services were also suspended earlier in the day but they have now been reinstated and are operating as normal.
Rain and wind gusts had caused some surface flooding, brought some trees down and caused an underslip on State Highway 1, which had since been cleared.
Auckland Emergency Management duty controller Rachel Kelleher told Morning Report officials were looking out for the weather expected mid-week as some more "adverse weather" could be coming through.
"We can all play a part in being prepared" - AEM duty controller Rachel Kelleher
"We will be looking to updated weather forecasts coming through this morning and encourage everyone else to do the same thing."
As a result of the severe weather already experienced this year, Kelleher said AEM was a lot more vigilant to what was happening and quicker to communicate with other necessary parties to deal with it.
She said everyone could "play a part in being prepared" by encouraging others to clear their street gutters if they saw anything blocking them before council cleared them.
Auckland's deputy mayor Desley Simpson told Midday Report the worst of the current bout of bad weather appeared to have passed for the city.
She said wind gusts peaked at about 93km/h at Whangaparaoa and most weather stations across the city had recorded rainfalls of between 25mm and 40mm overnight.
"The good news for us is there are currently no watches or warnings in place for Auckland."
But she warned more wet weather was expected later in the week and urged residents to keep informed in the event MetService issued any further alerts for the region.
Rough weather coincides with kiwifruit harvest
The heavy rain and wind could not have come at a worse time for kiwifruit growers in the Bay of Plenty.
Grower and packhouse director David Jensen said the gold kiwifruit pick was running a week behind, which meant the bad conditions had arrived in the busiest period of the season.
He said the fruit could not be picked in the wet, meaning seasonal picking staff could not work, and packhouses would likely start running out of fruit.
The rest of the kiwifruit would be left swinging on the vines until the weather had passed, Jensen said.
"We run the risk of a bit of wind-rub and the fruit slowly getting softer."
Kiwifruit is New Zealand's top export crop, with exports worth $2.8 billion dollars in the last financial year.