WITH the Eastern Bay having enjoyed one of the hottest summers on record, the warmer-than-normal trend is expected to continue through winter.
Bay of Plenty, along with Northland, Auckland and Waikato will see above-average temperatures while other areas will likely be above-average to average.
But the National Institute of Water and Atmospheric Research (Niwa) warns frosts and cold snaps will be more common, with the possibility of some cold snaps being quite sharp.
Niwa also warns of large rain events caused by lower than normal sea-level pressure and warmer than average Tasman Sea temperatures.
Rainfall levels are forecast to be above normal in areas, including the Bay, and near or above normal for the rest of the North Island.
The balmy first three months of 2018 has given New Zealand its hottest recorded start to a year, with mean temperatures reaching 1.75 degrees above average over the period.
The warming trend comes amid the hottest summer on record and the influence of a record-beating marine heatwave.
Niwa meteorologist Ben Noll said the region had broken the weather trend the rest of the country had experienced.
“Basically, the upper North Island (including Bay of Plenty) was the only place during the month of April that had above average temperatures, so much of the rest of the country had either average or below average temperatures,” he said.
As the temperatures were mainly influenced by a marine heatwave that recently began fading, Mr Noll said he doubted the temperatures would hold long enough to make the year a record-breaker.
With the marine heatwave having faded, Noll doubted whether 2018 would finish up as New Zealand’s hottest.
“By the time July wraps up, we also don’t expect the maps to be painted blue, meaning temperatures have been below average,” he said.
Soil moisture levels and river flows were expected to be near normal or above normal for all North Island regions.