Today is the coldest day so far this year for Aucklanders, and much of the country woke to early frosts this morning.
Frost in Tapawera, Nelson. (File photo). Photo: Tracy Hay
MetService says Auckland's low overnight reached the coldest temperature since June 2018.
"Air frosts were observed at daybreak in the inland valleys. Shout out to Ardmore, down to -1.1 Celsius this morning; OakenHill Farm -1.3C, Waiuku -0.2C, and good old Whenuapai and Henderson Valley which dipped to 0.1C ... Wrap up warm!"
The icy crystals were widespread. Clear skies with no cloud cover meant warmth in the ground dissipated out toward space, and the colder ground then chilled the air above, which produce frosts, meteorologist Andy Best said.
"We've had a ridge of high pressure over much of the country, and that's led to relatively clear skies for much of New Zealand. The clear skies have led to many places with severe frosts in the South Island - temperatures of -5 C or below."
Nationwide, the coldest places overnight were the Nelson alpine village of Saint Arnaud, which hit a chilly -7.7 C, and Canterbury's Pukaki, at -7.6 C.
Through Friday, weather over most of the country is expected to stay fine, and frosts are expected tonight for most of the South Island, and in the North Island from the Bay of Plenty down through the central North Island to Hastings and Masterton.
Places that break the national trend and aren't likely to remain fine and clear today are Taihape, Taranaki, Whanganui, the east coast from Wairoa north to Gisborne; and Dunedin and Hokitika, where a front will approach through the day, Best said.
This weekend there are severe weather warnings for rainfall for Fiordland, Otago, Westland, Canterbury, the Alps, West Coast, Nelson, Marlborough and Taranaki. And a severe weather warning for strong northerlies for Marlborough, Wellington, Taranaki, Manawatu and Whanganui.