New Zealand weather: 'Concerning' start to summer

New Zealand is off to a "concerning" start to summer, after some of the worst rainfall patterns in over a century.

A NIWA monthly climate summary for November showed we suffered rainfall levels "well below normal" and temperatures "well above average" for many parts of the country.

"Several locations across the South Island and lower North Island observed exceptional dryness and, in some cases, came close to or broke rainfall records that had stood for over a century," NIWA meteorologist Ben Noll said.

"Low rainfall and very dry soils are concerning both from a meteorological and hydrological perspective, especially as New Zealand is heading into what is usually the driest season of the year."

Of the six main centres in November 2017, Auckland was the warmest, Auckland and Hamilton were the least sunny, Dunedin was the coldest, Christchurch was the driest, Wellington was the sunniest, and Tauranga was the wettest.

No rainfall was recorded in Orari at all for the first time in 120 years. Christchurch and Lincoln had a 35-day dry spells.

The highest temperature was 33.3degC, observed at Cromwell, and the lowest was -1.6degC, observed at Hanmer Forest.

Sea surface temperatures soared to record or near-record levels. SSTs were generally 1degC to 3degC above average for the time of year and up to 6degC above average in some areas.

When extreme weather events occurred, they caused floods, thunderstorms and lightning strikes.

Children had to be helped to school by police in Thames after flooding and broken powerlines left a road impassable.

A cold pocket of air caused several heavy showers and thunderstorms across the upper North Island. Cars were belted with hail, and cloud to ground lightning struck across the Auckland region.

Thunderstorms around Taranaki also caused ping pong ball-sized hail in Urenui.