Winter Cold Snaps 2025

The story so far

In mid-July 2025 the New Zealand Transport Agency warned of persistent freezing fog, hoar frosts and possible black ice on State Highways 8 and 80 in the central South Island.^{17 Jul 2025} A frosty, foggy spell spread across much of the country, and Otago primary and intermediate schools and Dunedin kindergartens delayed their start to 10am because of frost and black ice.^{21, 23 Jul 2025} The ice caused road crashes and flight disruptions in Canterbury and Dunedin, and some trains were suspended in Wellington.^{24, 25 Jul 2025} Frosts continued into August, with Alexandra reaching -4.4C and the South Island dropping as low as -6.2C, before cold fronts brought rain and snow, including a closure of the Desert Road.^{2, 7, 9, 12 Aug 2025}

Latest

Fine weather was forecast to give way to rain and wind, followed by cold nights as an unusually strong high arrived.^{15 Aug 2025}

Key moments

1. 17 Jul 2025NZTA warns of freezing fog and black ice on South Island highways.
2. 23 Jul 2025Otago schools and Dunedin kindergartens delay start to 10am because of frost.
3. 24 Jul 2025Black ice causes crashes and flight disruptions in Canterbury and Dunedin.
4. 25 Jul 2025Rotorua, Taupō, Dunedin and Masterton record their lowest temperatures of 2025.
5. 2 Aug 2025Alexandra hits -4.4C as widespread frosts continue into August.
6. 9 Aug 2025Snow closes the Desert Road section of State Highway 1.
7. 12 Aug 2025South Island temperatures reported as low as -6.2C, with more frosts forecast.
8. 19 Aug 2025Rain and thunderstorms forecast for North Island, with snow warnings in the South.

Written from the stories below; each sentence links to its sources.