"It's a cold, raw start to the day across much of the lower North Island," Mr Corbett said.
"There's still a band of that left-over rain from Kapiti to eastern parts of Wairarapa but that's fizzling out and it's just an improving picture for the day."
Wellington Electricity spokesman Drew Douglas said two power outages were caused by trees falling on powerlines last night.
The first, in Titahi Bay at 6.30pm, affected 921 customers. All were restored by 9.40pm.
A further 28 customers lost power in Plimmerton at 8.30pm, but all were restored by 10.50pm. There were no further outages overnight, he said.
A major landslide in Wellington does not appear to have been affected by stormy weather overnight.
Wellington City Council spokesman Richard MacLean said there had been no obvious movement in the slip during yesterday's heavy rain.
"But we'll be going back this morning with our inspectors to take a closer look and do more ground movement checks," he said.
Yesterday a digger was put at the foot of the slip in Kingston to dig channels for water, while pumps and a temporary stormwater drain had been installed at the top of the slip to direct water away.
Eight houses have been evacuated and remain off-limits while the council carries out further investigation.
MetService said clearer weather was expected right across the country today.
"There's a couple of little pinwheel areas of rain with some thunder up across from about Great Barrier Island up to eastern Northland. They'll spin away across the far north of the North Island during the day," Mr Corbett said.
"The rain might be a bit more persistent and linger in places like Gisborne and Hawke's Bay with the southeast flow, but it just improves everywhere."
Auckland was in for light winds and a showery day, with a chance of heavy falls.
WeatherWatch said the south had a frosty start this morning, with temperatures of -4C at Dunedin airport and -3C at Queenstown and Wanaka.
Timaru was also below zero, with clear skies and still conditions, said weather analyst Richard Green.
Snow fell to reasonably low levels late yesterday about eastern foothills, but not to the depth of the previous day across inland areas of the South Island, he said.
The complex low was still having an effect over the North Island, but conditions should settle by afternoon, said Mr Green.
"It's taking longer than we initially thought as this system is making hard work of it all but it is heading in the right direction and slowly leaving our shores."
NZTA has advised caution on SH1 from Oamaru to Dunedin, and SH8 from Twizel to Fairlie because of ice, while Arthur's Pass is restricted to vehicles with chains only because of snow.