There was widespread frost across Dunedin this morning, with early flights affected and motorists warned to take care.
A flight scheduled to arrive from Christchurch at 7.40am and one to depart for that city at 8.10am were cancelled.
It was -6°C at Mosgiel and at the airport in Momona this morning.
Grit trucks were being used but the Dunedin City Council advised people to take care on roads and footpaths.
"Our contractors are out checking and treating main roads as required."
It was also a cold, frosty morning in Central Otago and Queenstown Lakes District, with dry roads and clear skies.
There were patches of fog around Clyde and temperatures ranging from -2°C to -6°C, a spokeswoman for the Central Otago District Council said.
"Caution is still advised in shaded areas and on bridge decks as these could be slippery especially around daybreak.
"Keep an eye out for excess grit, reduce your speeds and drive to the conditions."
In Queenstown, there were only a few slippery patches to be cautious of, a spokesman for the district council advised.
These included the Fernhill roundabout at One Mile and the odd spot on Glenorchy Rd heading out to Wilsons Bay. Precautionary grit had been applied on Mt Aspiring Road at the Glendhu Bluffs.
Over the Crown Range road, the CMA anti-freezing agent was doing its job where applied, with no major issues to report.
Temperatures early this morning ranged from -1° in Wānaka to -5°C at Albert Town and Hawea Flat; -5° in Arrowtown, -3° around Shotover Country and Jacks Point. It was -7° in the Lindis Valley but just above freezing south of Alexandra.
MetService said some of the coldest temperatures were in the Canterbury High Country and inland Canterbury.
Forecaster Matthew Ford said Mt Cook Aerodrome dipped down to -7°C overnight and in the high country Pukaki recorded -6°C.
- Allied Media and RNZ
