He noted maximum temperatures have also been colder.
“The average maximum temperature for Whangārei for May is 18.4C, and although it got to 18C on Friday and Saturday, no maximum temperatures have been warmer than average.”
He said rainfall has also been drier than average, with only 13.1mm of rain recorded this week.
“The monthly rainfall average for Whangārei is 114.1mm, which would be 28.5mm per week.”
For the rest of the month, normal or just below normal levels of rainfall are expected, accompanied by “roughly normal temperatures”, Bakker said.
Bakker said the difference between last year and this year came down to last May being unusually wet.
“Throughout most of May 2023, New Zealand found itself situated between a large, semi-permanent blocking high pressure system to the east of the Chatham Islands, and slow-moving lows in the Tasman Sea. This synoptic pattern resulted in a recurring series of heavy rainfall events for northern and western regions.”
National Institute of Water and Atmospheric Research (Niwa) meteorologist Chris Brandolino said Friday could be especially chilly and minimum temperatures could get as low as 2C.
“We are getting more southerly winds, and when we get southerly or southwesterly winds, it results in colder weather.
“If you want to peel it back a bit more, it’s because of El Nino. Even though [El Nino] is fading, it is expected to last longer.”
He said next week we will see moderate temperatures that “may not last long, but there will be some relief in six or seven days”.
“We expect that even though we are in a cold snap now; [during] May, June and July as a collective, we are expecting average or above average temperatures. “
He said as far as rainfall is concerned, they expect it to be drier than usual, which may not be good for upcoming spring and summer seasons.
“It doesn’t mean it won’t rain; [there] will be less than we expected. The soil temperatures are unusually dry for this time of year, and if that persists in the wet season, that won’t be good for spring. This is the time we want the soil to recharge.”
According to Northland Regional Council’s April 2024 climate report, which was released this week, the end of autumn is set to be cooler than usual.
“El Nino has continued to ease throughout April and is expected to be classified as neutral Enso conditions by the end of May. La Nina is expected to develop in spring, though we can’t predict how strong that will be yet,” the report said.
