Desert Road reaches -10C, Timaru records coldest August day in 28 years

Several cities have recorded their coldest night this year as the cold snap continues to hit the country, while Timaru has recorded its coldest temperature in 28 years.

Rotorua has seen its lowest temperature this year - and for August since 2006 - at -4.4C, and so have Napier and Hastings at -2.6C.

Napier's temperature is the coldest for August, also since 2006.

Timaru recorded -6.1C - the coldest morning it's had since 1998.

MetService earlier told RNZ it was the coldest morning in 46 years, since 1980.

Desert Road was -10C, the coldest place across the country overnight, with MetService saying there is lots of frost on the road, and the possibility of black ice.

Auckland recorded -2C at Whenuapai Airport.

Temperatures are expected to lift over the next few days, MetService said.

"We've got a frontal system moving in from the west on Saturday that will mean northerly winds and warmer moist air and some rain, so that'll be the end of the clear skies and light winds, which are the conditions you need for very cold overnight temperatures," he explained.

"Into early next week we're not expecting any minimums in the order of what we've seen the last two or three nights."

Overall, he said Friday's conditions would be very similar to Thursday's.

"The North Island's going to be pretty similar, if anything maybe a touch colder, but very similar," he said.

"[But] over in the east, expecting it to be a good deal colder this morning because the cloud cover's dissipated there and moved offshore, so Napier and Hastings going to -4, and then Dannevirke and Masterton -5, so they'll be a good deal colder."

"In the South Island, not a great deal warmer but a touch warmer."

Of the cities, he said morning commuters in Wellington would be best off.

"Wellington's probably going to be the warmest city around, the Hutt Valley might get down around freezing but in the city itself maybe 4 or 5 degrees [during the morning]," he said.

"Auckland's in the low single digits, 1 or 2 maybe, and Christchurch going to -3."

Temperatures would remain brisk on Saturday morning, but start to warm up.

"We've probably got another [cold day] for parts of the North Island on Saturday morning, but nothing like the last couple of days," he said.