The wintry conditions moved up the East Coast of the North Island yesterday, closing schools and roads, cutting power and phone lines and stranding up to 1000 bus passengers.

But the snow, heavy rain and high winds that hit areas around the East Cape, Gisborne and Hawkes Bay were expected to move offshore overnight.

"It was another really cold and wet winter's day, but it should be a gradual improvement from now on," said MetService forecaster Gerard Bellam.

Poor weather and safety concerns forced Telecom workers to retreat from a telecommunications mast in Te Araroa, near East Cape, which had been struck by lightning about 10am, cutting phone lines to 600 homes.

"We've had reports that it caused phone jacks to explode or melt, and phone lines are down," said Gisborne Civil Defence spokesman Paul Stuart.

Telecom workers also had to wait until today to get to a wind-damaged antenna in Elsthorpe, Hawkes Bay. The damage had cut a further 60 home phone lines.

Treacherous road conditions forced InterCity to cancel one-third of its North Island bus services yesterday, affecting up to 1000 passengers.

"We ran some Auckland to Wellington services via New Plymouth, but services through the central North Island and out to Napier and Gisborne were all cancelled," said chief executive Malcolm Johns.

Electricity company Eastland Network reported outages to Wairoa, Mahia and north of Tolaga Bay, with residents facing up to four days without power.

Meanwhile, snow down to 500m fell in mountain ranges inland from Gisborne and Hawkes Bay, trapping several trucks on State Highway 2 between Gisborne and Opotiki.

Heavy rain causing slips and surface flooding closed the road from Gisborne to Wairoa, halting postal services to both towns.

The road reopened but as the rain moved north, schools closed and police advised people not to drive unless absolutely necessary.

Areas around Gisborne were hit with 100mm of rain by mid-afternoon - about a month's rainfall - while 54mm fell in town amid 70 km/h gusts.

Several trucks sat abandoned on the roadside as State Highway 5 from Napier to Taupo remained closed overnight, as did State Highway 38 from Rotorua to Wairoa.

Snow flurries continued to dust the central North Island - where all access roads were cut off on Thursday - and the Desert Road remained closed overnight.

But other roads reopened, bringing some relief to dozens of stranded travellers.

Transit NZ Hamilton area engineer Alan Burkett said staff had worked around the clock to clear snow over a wide area, and they would monitor conditions overnight. He warned that high winds in the morning would make roads icy.

Canterbury snowstorm up there with the worst

* The snowstorm that struck the South Island on June 11-12 brought between 75cm and 90cm of snow to the townships of Fairlie and Burkes Pass in the South Island's Mackenzie district. The coastal towns of Ashburton received 38cm and Timaru 24cm.

* The last similar-sized storm was on August 5-6, 1973, when 90cm of snow fell at Methven, in Mid-Canterbury, when 100,000 sheep were killed and the power supply and communications were badly disrupted, as in the latest storm.

* In November 1967, between 60cm and 90cm fell in the South Island's Mackenzie district. Up to 70,000 sheep were killed, there were widespread power outages and crop losses, and some called it the worst snowfall in living memory.

* The coldest official temperature recorded since last week's snowstorm was -14C at Tara Hills, near Omarama, as severe frosts followed snowfalls.

* On Tuesday, a temperature of -13C was recorded at Fairlie, the second-lowest temperature for June on record.

* Niwa said 68mm of rain fell in Hawkes Bay on Monday and 55mm in the 24 hours to 9am yesterday; MetService reported about 70mm of rain in 12 hours yesterday.