Heavy rain is expected to hit parts of central New Zealand on Monday.

Metservice says a low pressure system over the Tasman Sea is approaching New Zealand today, bringing periods of heavy rain.

A Heavy Rain Warning is in force for Nelson west of Motueka and Mt Taranaki.

A Heavy Rain Watch covers northern Buller, the remainder of Nelson, and northwestern parts of Marlborough, and now includes Tongariro National Park, Tararua Range and the ranges of eastern Bay of Plenty.

A statement issued by Weather Watch says the low is moving in slowly with a period of rain tonight and Monday moving down the North Island.

'The set up will see hit and miss relief with the rain widespread but the heaviest more helpful downpours a bit more localised.”