Earth Sciences New Zealand climate scientist Gregor Macara said between June and the end of August, the mean sea-level air pressure was higher than normal over and to the southeast of New Zealand.
This brought more easterly winds than normal for southern parts of the country, and fewer cold westerly winds than normal.
Temperatures were above average for much of the West Coast, coastal South Canterbury, Dunedin and Fiordland; and near average for remaining parts of the region.
No locations observed below average winter temperatures, he said.
With mean air temperatures of about 9°C over winter, Puysegur Point in Southland (9.8°C) and South West Cape on Stewart Island (9.3°C) had their warmest winter on record.
Nugget Point (7.6°C) and Tautuku (7.7°C) had their third-warmest winter on record.
Milford Sound set a record mean maximum air temperature for winter with 11.4°C - its highest since records began in 1934.
Puysegur Point (11.9°C) and South West Cape (11.3°C) also set records.
Mr Macara said relatively high temperatures occurred over the southern regions on July 28 - particularly in Milford Sound (19.3°C) and Puysegur Point (18.4°C), where daily maximum temperature records for winter were set.
The highest winter temperature in New Zealand was on June 5, when the mercury reached 23.2°C at Whakatu, and the lowest was -12.9°C at Mt Cook airport on June 8.
The nationwide average temperature in winter 2025 was 9.1°C, making it New Zealand’s ninth-warmest winter since Earth Sciences New Zealand’s seven station temperature series began in 1909.
Winter rainfall was above normal or well above normal for Dunedin, but below normal in parts of Otago and coastal Fiordland.
Lumsden (47mm) and Ettrick (60mm) set winter extreme one-day rainfall totals on June 27 and June 29, respectively, and Alexandra had its second-highest extreme when 34mm fell on June 27.
The highest one-day winter rainfall in New Zealand was 164mm, recorded at Motueka on July 11.
However, August 2025 on its own, was a different kettle of fish, he said.
It was characterised by fine and settled weather, due to the prevalence of high mean sea level pressure over the country.
It meant places such as Middlemarch recorded just 7mm of rain (12% of normal), making it the driest August on record.
And the lack or rainfall meant there was ample sunshine during August, particularly for Franz Josef (197 hours), Aoraki/Mt Cook Village (156 hours), Middlemarch (189 hours) and Dunedin (173 hours), which had their highest August sunshine hour totals on record, he said.
