7th-warmest winter on record and near normal rainfall
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Temperature |
Temperatures were above average (+0.51°C to +1.20°C of the winter average) or near average (-0.50°C to +0.50°C of the winter average) for most of the country. Winter temperatures were well above average (> +1.20°C of the winter average) about the Mackenzie District and parts of Otago and Southland. |
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Rainfall |
Rainfall was near normal (80-119% of the winter normal) for the majority of the country. Small pockets of below normal rainfall (50-79% of the winter normal) were observed about Gisborne, Hawke’s Bay and parts of Otago. |
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Soil moisture |
At the end of winter 2019, soil moisture was near normal for most of New Zealand. Soils were drier than normal for isolated parts of inland north Otago and wetter than normal about Kaikoura. |
Overview
Winter 2019 began on a chilly note, with snow falling in the South Island and the Central Plateau on 1 June. The wintry start was however not indicative of the season as whole, with snow events infrequent throughout the season. June was the driest winter month with below or well below normal rainfall for the majority of New Zealand. Several locations in southern coastal Canterbury and northern coastal Otago observed one of their driest Junes on record. While July wasn’t as dry as June, a distinct lack of southerlies and frequent rounds of high pressure during the month led to unseasonably warm temperatures and New Zealand’s second-warmest July on record. August was unsettled, characterised by frequent low pressure systems and a strong southwesterly flow – a pattern driven by a strongly negative Southern Annular mode early in the month. Frequent fog events, thunderstorms and tornadoes occurred during winter.
The winter climate pattern was influenced by a polar jet stream that remained south of New Zealand during June, was weaker than normal in July, but occasionally passed over the country during August while interacting with the sub-tropical jet stream. This contributed to an unsettled end to the winter season. In the tropical Pacific, a central Pacific (Modoki) El Niño persisted during June and July before fading to neutral in August. New Zealand coastal sea surface temperatures were above average for the season. These two factors tipped the odds toward a warmer than average winter season for many locations.
Winter as a whole saw average to above average temperatures across the country. The nationwide average temperature for winter 2019 was 9.0°C (0.6°C warmer than the 1981-2010 winter average, using NIWA’s seven-station temperature series which begins in 1909). This makes the winter of 2019 the seventh-warmest winter on record.
Further Highlights:
- The highest temperature was 21.6°C, observed at Wakanui on 3 July.
- The lowest temperature was -9.2°C, observed at Lake Tekapo on 3 June.
- The highest 1-day rainfall was 126 mm, recorded at Milford Sound on 13 July.
- The highest wind gust was 182 km/hr, observed at Cape Turnagain on 13 August.
- Of the six main centres in winter 2019, Auckland was the warmest, wettest and sunniest, Dunedin was the driest and least sunny, while Christchurch was the coolest.
