Auckland is forecast to slowly reach a high of 15C today, with showers, hail and thunderstorms. It will get a crisp overnight low of 8C.
The system was moving fast, so the heavy downpours were brief.
Wind gusts of about 100km/h were recorded about the Waikato and Waitomo coast.
In the South Island the cold snap had deepened, as temperatures dropped to -6C in parts of inland Southland and Central Otago, Naeraa-Spiers said.
Heavy snow was forecast overnight above 400m in Fiordland, Westland south of Haast, Southland north of the Mavora Lakes and the western ranges of Otago south of Mt Aspiring.
No more snow was reported overnight, but by yesterday evening about 50cm had fallen on the Milford Rd, 25cm through Arthurs Pass and 5cm in Queenstown.
"It all depends on how high up you get," Naeraa-Spiers said.
Snow showers were forecast on many of the country's roads at higher altitude to 11am today.
The Desert Rd (SH1), Lewis Pass (SH7), Arthurs Pass (SH73), Porters Pass (SH73), Haast Pass (SH6), Lindis Pass (SH8) and Milford Rd (SH94) are all under road snow warnings.
A slip has closed the Crown Range Rd, adding to issues with snow, Queenstown Lakes District Council said. It was expected to be closed until 10am.
Many of the South Island skifields were treated to decent snowfall too: more than 50cm was recorded in some Canterbury skifields, Naeraa-Spiers said.
"The old saying was, 'snow in May melts away', but as we near June it is cooling down and it might not be the case."
More snow showers are forecast over the next few days as another cold southerly flow spreads over the country tomorrow.
Auckland and Northland are in for a rainy weekend and relatively cold temperatures struggling to get above the mid-teens.
Eastern areas including north of Wellington will also see some showers and brutally cold southerlies, but the South Island becomes relatively fine.
"Especially on the West Coast, which has seen a lot of severe weather lately," Naeraa-Spiers said.
Another cold snap is forecast for Sunday and Monday, and more snow in parts of the South Island.
Overnight temperatures across the country are forecast to plummet even further, and even Auckland drops to a low of 6C on Monday.
"There could be some really cold nights over the next couple of days," Naeraa-Spiers said.
By Tuesday a ridge of high pressure is forecast to move across the country, finally bringing relatively settled weather.
"By then it should settle down for a while, fingers crossed," Naeraa-Spiers said.
Today's weather
Whangārei Showers with hail and possible thunderstorms, easing evening. Westerlies. 17C high, 9C overnight.
Auckland Showers with hail and possible thunderstorms. Westerlies. 15C high, 8C overnight.
Hamilton Showers with hail and possible thunderstorms. Westerlies, strong and gusty in the morning. 14C high, 4C overnight.
Tauranga Showers with hail and possible thunderstorms. Westerlies dying out evening. 15C high, 6C overnight.
New Plymouth Showers with hail and possible thunderstorms. Strong westerlies changing southeast evening. 15C high, 6C overnight.
Napier Fine with high cloud. Chance shower from afternoon as strong northwesterlies turn southerly. 17C high, 5C overnight.
Wellington Fine, with high cloud, but showers developing from afternoon as northwesterlies turn strong southerly. 12C high, 7C overnight.
Nelson A cloudy start, then becoming fine by midday. Light winds. 13C high, 1C overnight.
Christchurch Showers about Banks Peninsula morning, spreading elsewhere afternoon, some heavy with hail. Northwest changing southwest afternoon. 10C high, 3C overnight.
Dunedin A morning shower or two becoming more frequent in the afternoon, some heavy with hail. Cold southerlies. 9C high, 5C overnight.
