A wet and windy end of the weekend for many parts of the South Island

MetService has issued heavy rain warnings for Buller, Westland, parts of Canterbury and the headwaters of the Otago lakes and rivers - all coming into affect from later today.

The Grey District, Tasman, Taraua Ranges and Taranaki are all under a watch.

Meteorologist Devlin Lynden says there's also strong wind watches in place for Wellington, Marlborough and the Canterbury High country.

He says gusts could reach up to 100 kilometres an hour between 6pm and 6am.