Today was a shorts and T-shirts weather as parts of Otago get their first taste of summer, including Dunedin which recorded the country's highest temperature mid-afternoon.
The MetService had forecast 19degC for Dunedin, but just before 3pm the city hit 21degC.
Alexandra was also expected to reach 19degC, and 20degC for Mosgiel and Oamaru.
However, Queenstown, Wanaka, Balclutha and Southland are not expected to share in the glorious weather.
Rain or showers, and a high of about 16degC, was forecast.
The balmy weather is caused by an active front, preceded by strengthening northwesterlies, forecast to move north across the South Island tonight and tomorrow morning.
A MetService spokesman said the front was expected to bring a period of heavy rain to the West Coast, and a heavy rain watch was in force for Fiordland and Westland, south of Otira.
The northwesterlies were expected to rise to gale-force ahead of the front and a watch has also been issued for the possibility of northwest gales becoming severe in exposed parts of Central Otago and the Southern Lakes.
Today's warm temperatures are not expected to last.
A cold front is forecast to approach the South Island from the south Tasman Sea on Sunday, then move northeast over the island on Monday.