The explosive thunderstorms that hit the North Island yesterday should ease but heavy rain and plummeting temperatures are forecast for the rest of the week.
WeatherWatch analyst Philip Duncan said last night's intense thunderstorms were sparked due to unusually warm temperatures.
The organisation did not receive any reports of damage, he said.
"They were explosive and some of the most vigorous thunderstorms I've seen in Auckland. Not very often do you see the more American-style thunderstorms with almost non-stop lightning.
A colder June than usual is on the cards for the rest of the month, meteorologists say.
MetService meteorologist Georgina Griffiths said the below-average temperatures expected this month were in sharp contrast to last year which had the warmest June on record for New Zealand.
The first and last weeks of the month look particularly icy and sea temperatures around the country were cooling off faster than usual, Ms Griffiths said.
"Sea temperatures are important for us because to a certain extent they influence air temperatures in our coastal regions.
"June starts pretty wet and wild, with the risk of extreme rain or snow in the mix. But, as the month progresses, the weather is likely to settle back to more typical early-winter patterns."