Just as New Zealand is divided into North and South Island, so too is the weather story for Waitangi weekend.

As plans are made for the long weekend a low over the north Tasman Sea is expected to move slowly eastwards and passes north of the country, stretching a band of rain over the upper North Island.

A rain band is slowly making its way down the country.

In contrast, a ridge lingers over the South Island all weekend bringing mostly settled weather.

Another wave of humid air wafts over the country this Waitangi weekend, as a low in the north sucks warm air down from the subtropics, says a statement from the MetService.

A strong, moist northeast wind ahead of the low is forecast to bring periods of rain to northern New Zealand from Friday, with some heavy falls possible into Saturday for areas from Northland to eastern Waikato and across to Coromandel Peninsula, Bay of Plenty and northern Gisborne.

Friday will be wet and windy in the north, then the rain band sinks south and east on Saturday, although there is still the potential for showers over eastern areas of Northland.

This weekend many other areas along the east coast of the North Island and also from Taranaki north, will see some rainfall, but weather improves from Sunday, with Monday looking like the best day for many North Islanders.

'If you are going to the Waitangi Festival or celebrations for Waitangi in Auckland it might be a good idea to pack a light rain coat,” says MetService communications meteorologist Lisa Murray.

'And if you're off to the Rugby 9's, it won't be cold but with wet weather in the forecast a showerproof costume may be the winner on the day.”

Farther south, Wellington stays dry for the Blackcaps in Westpac Stadium and Waitangi celebrations on Saturday, while Monday's cricket looks dry in Hamilton too.