Rain, snow and gales - the outlook for weather for the week ahead is looking to be colder and windier across New Zealand.

"During Tuesday a frontal rain-band moves northeast across the country, bringing rain to many areas and north to northeast gales to exposed places," says a MetService spokesperson.

"On Wednesday, a large and active trough of low pressure over the Tasman Sea starts to move onto the country, with northwesterlies strengthening over the North Island, and colder, strong or gale southerlies developing over the South Island."

MetService says snow is expected to lower to around 400 metres over southern New Zealand for a time, which could affect a number of higher roads.

"On Thursday, the cold southerlies spread over the North Island. A ridge of high pressure builds over the country on Friday, with winds easing."

For Southland and eastern parts of Otago, MetService says there is moderate confidence of warnable amounts of rain on Tuesday and Wednesday.

For Fiordland and Westland, there is high confidence that warning amounts of rain will fall during Tuesday.

For Buller, Nelson/Tasman and northern Marlborough, there is high confidence that warning amounts of rain will fall during Tuesday, and moderate confidence on Wednesday.

For the Tararua Range, and North Island areas from North Taranaki across the central high country to Bay of Plenty and northwards, there is moderate confidence for warning amounts of rain on Tuesday, which continues for central areas and the Tararua Range into Wednesday.

"Additionally, on Tuesday there is low confidence of severe north to northeast gales about Auckland, Taranaki and Wellington.

"Also, on Wednesday and Thursday, there is low confidence of severe south to southwest gales about Banks Peninsula."