Parts of the South Island's east coast could be in for record warm weather this weekend.

MetService meteorologist Lewis Ferris says the east of the South Island will start the weekend with warm weather, with temperatures in Christchurch and Kaikoura reaching up to 28 degrees on Sunday.

He said that would be close to a record for October, but it would be soon followed by a frontal system bringing heavy rain.

"Most of that rain is going to fall on those western areas of the South Island. We do have a heavy rain watch currently in force from Sunday, it's looking likely that will be upgraded to an orange warning.

"The places that need the rain most - so, the eastern parts of the South Island from about Dunedin up to Christchurch - they will get some rain but it's not looking like large amounts for them."

Ferris said most of the rainfall would be on the West Coast, which had a heavy rain warning for Sunday.

He said the east of the South Island would get some rain on Monday, before it heads to Wellington later in the day.

New Zealanders have been warned to stay safe on the roads and continue with public health measures to combat the Covid-19 coronavirus over the long weekend.