New Zealand posts third-warmest winter since 1909 as South Island warmth lifts national average

Winter 2026 ranked as New Zealand’s third-warmest on record, Earth Sciences New Zealand reported, after the country recorded a nationwide mean temperature of 9.7°C — 1.1°C above the 1991–2020 seasonal average.

The ranking is based on the agency’s seven-station temperature series, which begins in 1909. Officials said the outcome may surprise many in the north, where conditions were closer to normal. The national figure was instead driven by unusually warm weather in June across the country and a persistently mild winter across the South Island.

Temperatures were above average or well above average throughout the South Island and across much of the North Island. Near-average readings were confined to parts of Northland, Auckland, Waikato, eastern Bay of Plenty and Gisborne.

Rainfall patterns were sharply split. Totals were above or well above normal in Southland, Otago, southern and inland Canterbury and the West Coast. Large areas of the North Island were drier than usual. Heavy rain from 5–9 July hit eastern districts and prompted three local states of emergency.

The season’s highest temperature was 26.0°C at Bromley in Christchurch on 20 June, New Zealand’s second-highest winter reading on record. The lowest was −13.5°C at Lake Tekapo on 12 July.

El Niño conditions in the tropical Pacific strengthened markedly from mid-winter. Sea-surface temperatures around New Zealand were mostly near or above average, and marine heatwave conditions developed around much of the South Island and the Tasman Sea in July and August.

Scientists noted that El Niño typically favours stronger and more frequent southwesterly to northwesterly winds, producing drier weather in eastern and northern districts of both islands and wetter conditions in the west and lower South Island — a pattern broadly consistent with the winter just ended.