MetService News Release
02 June 2016
Buckle in for winter
May 2016
It was an extremely mild May across the country, due to the combination of frequent northwesterlies and warmer than
usual seas around the country. The first half of the month was exceptionally warm, and even with the wintry end to the
month, many new May temperature records were set. It was the warmest May on record for five of the six main centres
(Auckland, Hamilton (Ruakura), Tauranga, Wellington and Christchurch), with Dunedin observing its third warmest May. The
frequent northwesterly winds produced extreme rainfall for the West Coast South Island - it was the wettest May on
record for Hokitika (579mm of rain observed) and Milford Sound (1338mm). It was also wet for Nelson, parts of Southland,
Otago and south Canterbury, and the southwest North Island.
The Ocean
The 2015/2016 El Nino has ended, and the tropical Pacific Ocean has returned to a neutral state. The Tasman Sea and
Southern Ocean will rule our weather patterns through early winter, with the chance of La Nina development about 75% by
spring (double the normal odds). Sea temperatures around New Zealand remain above average, with the exception of the far
south of the country.
The June Outlook
June starts off unusually cold (and frosty), before well above average temperatures return next week. Over the second
half of June, temperatures look likely to continue to swing widely week-to-week. The monthly temperatures will likely
end up on the warm side of the ledger, but overall, large temperature swings are expected in June.
Similarly, rainfall is forecast to swing widely week-to-week. The first week of the month runs abnormally dry under High
pressure, while the second week looks very wet for most areas (excluding eastern regions) due to prevailing northerly
winds. The third week of the month is predicted to run on the drier side for most of the North Island and the north and
east of the South Island under a westerly regime, while the end of June shows useful rainfall across most regions.
Bottom line: Large swings in temperature are expected in June for all regions. Above normal June rainfall totals are signalled for
the West Coast South Island, Buller and Nelson, Northland, Auckland and Coromandel. Below normal June rainfall is
forecast for Gisborne, Hawkes Bay and Wairarapa. Elsewhere, near normal June rainfall is expected.
ENDS