Monster swells have begun smashing coastlines across the North Island.

In Pukehina, Bay of Plenty, waves have reached 6.4m.

They have also reached 5.9m in Tauranga and 4.3m further north at Marsden Point near Ruakaka, Northland.

Significant heavy rain and strong winds are due to hit up and down the country on Tuesday.

Orange heavy rain warnings were in place for Auckland, Coromandel Peninsula, Bay of Plenty, Central North Island mountains, Taranaki Maunga, Tasman, Nelson, Marlborough, the Westland ranges, and at the headwaters of Canterbury and Otago lakes and rivers.

Some strong wind watches were also in place for parts of the North Island.

MetService said the severe weather was caused by a front moving eastwards, and was expected to last into Wednesday morning. It advised people to keep up to date with the latest warnings and watches.

-RNZ