Further south, Dannevirke will receive much of the same conditions but the high today will be a chilly 7C, with highs for the remainder of the week barely reaching 10C.
WeatherWatch head weather analyst Phillip Duncan said a developing low caught up in the new cooler south west flow is set to bring rain across the entire western side of the North Island overnight tonight.
"The low is very weak but the rain could be heavy in places with even isolated thunder and hail as the colder air behind it sweeps in," he said.
"By Thursday afternoon the low will engulf a large portion of the North Island bringing rain or showers and plenty of cloud. And if you have wind coming in from the north, don't expect it to be warm like last week.
"Due to the shape of the incoming high over the South Island, and this low over the upper North Island, the air coming in over northern New Zealand is really being dragged out of the South Ocean."