RNZ among other outlets is reporting that a persistent high-pressure system is delivering well below average temperatures and an unusually cold winter thus far in New Zealand.
“A high-pressure system over New Zealand is likely to mean clear skies but could also lead to freezing temperatures that last all day in parts of Central Otago,” RNZ says. New Zealand’s National Institute of Water and Atmospheric (NIWA) Research and its MetService report the high-pressure system is delivering unusually cold temperatures.
“In parts of Central Otago like Alexandra and Clyde, a phenomenon called an inversion may cause the fog and freezing temperatures to last all day!,” said NIWA.
Sub-zero temperatures were forecasts for both the North and South Island, including a wide swath of Canterbury and Otago on July 11. The MetService expected overnight low temperatures dropping to -2℃ at Waikato and Taupo on the North Island on that same date.
This is part of an extended cold spell in July, noted RNZ with Mount Cook airport reporting its coldest temperature in 2024 a week earlier on July 4, when temperatures dipped to -7.1℃.
New Zealand’s cold start to winter was also discussed at Electroverse which reported:
[…]temperatures plunging below freezing across the country, to -7.8C (18F) in Omarama … [with the] MetService’s Lewis Ferris explain[ing] that New Zealand is under a high-pressure system, with the combination of light winds, clear skies, and long nights leading = to some of the lowest temperatures seen in years.
“It’s been a cold, wintry start across much of the country, especially in the South Island,” Ferris noted.