During El Nino, New Zealand tends to experience stronger or more frequent winds from the west in summer.
Currently, New Zealand is experiencing La Nina but that will change to El Nino in January and February.
Summer air temperatures are very likely to be above average for the west of the North Island.
Meteorologist Chester Lampkin said the summer would come in two stages.
“From early to mid summer, it will be a typical summer – you will get some westerly fronts, it’ll be warm and humid and [you will] get some rain,” he said.
“The latter part of summer will be mostly fine with a lot more dry days, maybe some hotter days, but not as humid.”
Lampkin said the dry weather was a concern for most of New Zealand.
While the rainfall total was expected to be normal or below normal, there was an increased risk of significant heavy rain events in late summer.
Lampkin said it was difficult to know what Whanganui’s average temperature could be throughout summer, because it factored in the day and night temperatures.
He said warmer nights were on the cards because Whanganui was aligned with most of the North Island in experiencing warmer-than-average water temperatures.
“You get warm water, then you get warmer nights,” Lampkin said.
Fin Ocheduszko Brown is a multimedia journalist based in Whanganui.
