New Zealanders are battening down the hatches as two weather systems battle in the skies

A low over the north Tasman Sea is sinking southwards - bringing heavy rain and strong winds to the North Island and top of the South Island.

Northland, the Coromandel Peninsula, western Bay of Plenty and northern Tasman are under severe weather warnings.

MetService has also issued watches for the upper, central and western North Island, the Nelson Ranges and Westland.

Civil Defence have urged holiday-makers to pack up and go home, and are warning of hazardous driving conditions and the chance of floods.

Forecaster Aidan Pyselman says along with this system, there's a big strong high to the east of the Chatham Islands.

He says it's known as a blocking high, because it's slowing the progression of the system bringing rain - meaning it will hang around for days.