• Wellington Aiport was closed to air traffic Wednesday night
• Whanganui and Rangitikei remain in states of emergency
• Whanganui River reached its peak and is receding, low-lying areas have been evacuated
• Bay of Plenty and Coromandel were expected to get the heaviest rainfall overnight
• Rain has passed in most areas but the widespread flooding will take time to subside
• Nearly 200 schools and childcare centres were closed yesterday, further closures are possible today
• If your home has been flooded, take photos of all damage and check with your local council before starting a clean-up
All flights in and out of Wellington Airport were cancelled last night as heavy rain played havoc with flight control systems.
The shutdown was the latest disruption from the remnants of Cyclone Debbie, which has flooded homes, caused huge landslips, cut power to tens of thousands and closed roads and schools across the North Island.
Wellington Airport said airways instruments were affected by the weather conditions just after 8pm.
"All flights were immediately diverted or cancelled. The airways team are onsite and investigating.
"Around 10 domestic flights have been affected and international flights are not due to arrive until midnight."
Flight radars showed some planes were sent back to where they came from.
Air NZ flight 449 left Auckland at 7.14pm, headed all the way to Wellington, then turned around and flew back, arriving at Auckland again at 9.19pm, according to flight logs.
Wellington Airport spokeswoman Arpita Dutta said the airport didn't know how long the flight suspension would last.
She said if anyone had to stay overnight in the terminal, the airport would look after them.
If the situation didn't improve by midnight, international flights would also be diverted, Dutta said.
Some frustrated passengers were close to tears last night and others were getting angry at airport staff.
But the airport seemed to have learned from its experience a week ago when fog grounded flights.
Music was turned down, to allow travellers stuck overnight to try to get some sleep.
Blankets and pillows were handed out, while food outlets on the ground floor stayed open late.
Meanwhile a state of emergency remains in the Whanganui and Rangitikei districts as rivers in the area rose dangerously high.
Whanganui residents in low-lying areas were evacuated and the army brought in to help sandbag against floodwaters.
The Whanganui River was expected to peak at 13.3m by midnight overnight, leaving it likely to burst its banks and require flooding cleanup today.
The worst of the weather should now be over for the North Island, but not the South Island.
MetService meteorologist Brian Mercer said Northland, Auckland, Waikato, and the Central Plateau were bracing for thunderstorms overnight, but should be down to normal levels of rainfall today.
Wellington and Taranaki were forecast for heavy rain overnight, but should be drying up by this morning.
However, Mercer said strong wind and rain was looking likely for Kaikoura and Christchurch.
"That low that's been dragging all this warm moist air through is crossing the country overnight.
"There'll be quite strong south-westerly gales for parts of the South Island overnight [Wednesday] and [today], and they'll be sticking around until the evening.
"The east coast will also get persistent rain and heavy falls, mostly in the morning."
Yesterday's damage from the wild weather has caused headaches around the country.
Many Whanganui residents spent the night huddled in Whanganui Girls College, or St Paul's Church, after being evacuated.
The Whanganui River was expected to breach at Kowhai Park overnight, causing flooding in low-lying areas.
Part of Taupo Quay was closed as a precaution, with cordons and security personnel in place, as well as sandbags around businesses.
In Auckland, the city was pummelled with more rain in 24 hours than it would usually see in the entire month of April.
In the chaos, 20,000 Transpower customers lost power for several hours.
Most of the problems were caused by trees falling on to powerlines, power poles falling over in loose ground, or slips.
Vector also suffered problems. While many were reconnected by yesterday evening, Vector technicians had trouble reaching parts of Clevedon, Tapora and Takanini.
Work there continued into the night.
In Kohimarama, apartment dwellers were forced to claw through rubble to find a man who went missing after their apartment block was hit by a landslide.
Mud and debris poured into the San Remo apartments late Tuesday night, causing a panic when residents realised one man was missing.
Thankfully, he turned up about 45 minutes after the landslide hit.
With everyone accounted for, yesterday was spent getting an engineer to assess the building, and residents trying to clear out the debris.
Auckland's Civil Defence also assessed several clifftop houses on the North Shore perched above a slip, and remained alert for more trouble overnight.
Duty officer Dion Anderson said staff would continue to monitor the situation and take calls at all hours.
"We will continue to work with the council's stormwater and building control teams, our contractors, and Auckland Transport on clean-up efforts.
"There are still some areas we need to keep a close eye on as the region is very saturated, and some floodwaters will take time to subside."
Further south, schoolchildren were stranded in Port Waikato overnight.
Around 100 children from David Street School, along with 30 parents and teachers, were stuck in a camp after slips blocked roads in and out of town.
Campground caretaker Simon Cave said the rain put a dampener on things, but they carried on with outdoor activities like abseiling.
He said they were prepared for the bad weather and had supplies to last them the night.
Across the country, 103 schools and 92 early learning centres had to close.
The closures affected 13,725 school students, and 3895 pre-schoolers.
The worst affected areas were Whanganui District and Rangitikei District, because of the state of civil emergency declared by their district councils.
Ministry of Education's deputy secretary of sector enablement and support Katrina Casey said further closures were possible today, as the severe weather was forecast to continue in some areas.
"For schools outside the civil emergency districts, the best information will come from schools and early learning services themselves as they make decisions about closures.
"Parents are advised to check their websites or Facebook pages, or contact them directly."