South’s summer warmer, sunnier and drier

While 2025 got off to a cool start, leaving many in Dunedin to ponder whether we have just had the worst summer in living memory, Niwa data shows the city was warmer, sunnier and drier than average over the season.

Niwa climate scientist Gregor Macara said Dunedin had its third-highest summer sunshine total on record with 675 hours, and between the start of December and the end of February the city recorded a higher-than-average mean temperature of 15.5°C (0.7°C above average).

The city also recorded just 156mm of rainfall during the season — 74mm below normal.

Mr Macara said summer 2024-25 was characterised by higher-than-normal air pressure over and surrounding New Zealand, which contributed to a mild and dry season for many areas overall.

However, cooler and wetter conditions were experienced in some eastern parts of the South Island — particularly Christchurch.

He said summer temperatures were above average for much of Otago and Southland, and well above average for most of the West Coast and Wānaka.

Franz Josef and Clyde recorded their second-highest mean maximum air temperatures for summer when the mercury hit 21.8°C and 26.1°C respectively, while Greymouth and Manapouri (West Arm Jetty) recorded their third-highest with 21.4°C and 21.1°C respectively.

At the other end of the scale, Balclutha recorded its second-lowest daily minimum air temperature for summer, when the mercury dropped to 0.5°C on December 17.

The highest temperature of the summer was 34.8°C, observed at Kawerau on December 29, and the lowest temperature was -0.4°C, at Waipara River North Branch, on January 25.

Mr Macara said Greymouth had the highest one-day rainfall when 154mm fell on December 15, but on the whole, summer rainfall totals were below normal or well below normal for the West Coast, much of Otago, and southern and western Southland.

The lack of rain left soil-moisture levels lower than normal for parts of the West Coast, and coastal parts of the South Island from Dunedin to Invercargill and Stewart Island.

Ōkārito (West Coast) recorded its lowest summer rainfall total with just 534mm; and Mt Cook Airport (324mm), Clyde (60mm) and Oban (Stewart Island) (168mm) recorded their second-lowest summer rainfalls.

The dry conditions and strong winds fanned a large fire at Tiwai Point (near Bluff) from January 29-31.

It burnt through about 1200 hectares, its perimeter measured about 18km, and 10 helicopters, nine fire appliances and 40 firefighters were deployed to fight it.

In another extreme weather event, large hail occurred between Beaumont and Lawrence, which dented cars and broke windscreens in Hunt Rd, on February 18.

Nearly 4000 lightning strikes were recorded across parts of Otago and Canterbury during the thunderstorm.

Mr Macara said overall, summer 2024-2025 was only the 21st-warmest summer on record, with a nationwide average temperature of 17.3°C.

‘‘This was 0.5°C above the 1991-2020 summer average from Niwa’s seven-station temperature series which began in 1909.’’