New Zealand’s weather is proving no exception to the record-breaking extremes occurring around the globe.
Analysis undertaken by NIWA meteorologists revealed that the first six months of 2022 have been New Zealand’s second warmest on record.
With an average national temperature of 15C, the period of January - June was 1.2C above the long-term 1981-2010 normal, according to NIWA’s Seven Station Temperature Series that began in 1909.
Relative to their respective monthly averages, May was the warmest month and February the coolest month.
Of the 10 warmest January-Junes on record, five have now occurred since 2016, with 2016 being the warmest (1.4C above average).
The first six months of 2021 were the ninth warmest on record, but the heat of the final half of the year made 2021 New Zealand’s warmest year on record.
2022 monthly temperatures and rainfall anomalies. Image: Ben Noll.
Rainfall has also been a story of extremes. For Southland, southern Otago, and Stewart Island/Rakiura, abnormally dry or drought conditions developed during summer. The dryness persisted and became more widespread during autumn, resulting in MPI’s classification of a medium scale adverse event for Southland, Clutha, and Queenstown-Lakes. Abnormal autumn dryness in Waikato and South Auckland led to a medium scale adverse event classification in May.
The impact of ex-tropical cyclones and abundant moisture caused a very wet start to the year across Hawke’s Bay and Gisborne.
What’s in store for the rest of the year?
Despite a wet and stormy start to July, temperatures for the majority of the country remain above average for the time of year.
NIWA meteorologist Ben Noll says that the continued influence of La Niña on New Zealand’s climate should continue to keep temperatures on the warmer side for the remainder of 2022.
Temperature and rainfall differences from 1981 - 2010. Image: Ben Noll.
"It’s probably going to be another hot year when all is said and done. We will likely get occasional plumes of tropical moisture approaching from the north, the latter influenced by a negative Indian Ocean Dipole event. The prospect for more easterly-quarter winds could see western areas of both islands turn drier during spring, which will need to be monitored, particularly as summer approaches," says Ben.
"Later in the year, New Zealand’s coastal sea temperatures could again heat up following a record marine heatwave earlier in the year - this would see the odds for another warmer than average summer increase."