After a stunner of the weekend, Aotearoa will be seeing some heavy rain with possible thunderstorms for parts of the South Island.
"Here comes the cold front! A sharp contrast can be seen between the unstable frontal cloud approaching from the Tasman Sea and the monotone flat cloud around Aotearoa," MetService posted on Twitter.
A heavy rain warning has been issued for Fiordland and the ranges of Westland south of HariHari, according to MetService.
"A front makes landfall overnight tonight, bringing periods of heavy rain for some," it posted on Twitter.
"Periods of heavy rain are expected for these areas from 6:00am Tuesday morning, with thunderstorms also possible for Fiordland," MetService meteorologist Ashlee Parkes says.
"Scattered falls will spill further east into the Southern Lakes, across to Dunedin and south through to Southland in the afternoon and evening."
The majority of the country will remain dry, with mild afternoons but "kinda cold nights", according to WeatherWatch's analyst Philip Duncan.
Eastern areas of the South Island will see warmer than average temperatures.
Christchurch is forecast to hit a high of 22C on Tuesday and Blenheim looks to reach 23C on Wednesday.
The North Island will be mostly sunny with light winds. The east coast between Gisborne to Wairarapa may see some clouds at times.
But MetService warns unsettled conditions are back on the horizon for the weekend.