Gnarly weather is in store for the South Island today with thunderstorms and gale-force winds set to lash regions.

And while the north escapes with a largely gloomy, dank day, the capital can expect the wild weather to ramp up with gale-force winds and heavy rain forecast.

MetService duty forecaster Chelsea Glue said the west coast of the South Island, which was already experiencing heavy rain, should brace for squally thunderstorms after lunch.

Eastern regions can expect strong nor'westerly winds to ramp up over the day, with scattered rain forecast for Dunedin.

Advertisement

A number of wind warnings and watches have been issued for the south ahead of a series of storms.

Christchurch is expected to reach a balmy 25C and Dunedin 21C.

Ms Glue says the capital can expect to be buffeted by high winds during the day.

Heavy rain is expected to fall after dark with warnings out for the Tararua Ranges.

The wild weather is expected to affect much of the lower North Island.

While it will be a largely drizzly, grey day for the rest of the island, eastern regions will remain dry.

Auckland can expect a high of 21C with Wellington reaching 19C.