Temperatures in Southland remained in the mid-teens, but in Dunedin, Cromwell, Otematata and Ranfurly, they reached 19degC; in Alexandra it reached 20.1degC; in Palmerston it reached 21degC; and in Oamaru the mercury topped 22.5degC.
The MetService is forecasting warm weather around the east coast again today, where temperatures could reach 20degC.
But severe gale force west-to-northwesterlies and heavy rain have been forecast for western and central parts of the region.
A MetService spokesman said an active front was expected to move northwards across the area tonight.
Strong northwesterlies may approach severe gale force in exposed places throughout Otago and Southland between 4am and 8pm today, with gusts of up to 100kmh.
In addition to the possibility of severe gales, the front may also deliver a brief burst of heavy rain in western parts of the South Island, including the headwaters of the Canterbury and Otago lakes and rivers.
"People are advised to stay up to date with the latest forecasts in case parts of this watch are upgraded to a warning, or further areas are added."
In the headwaters of the Otago lakes and rivers, a period of heavy rain is expected between 8pm today and 2am tomorrow.
"Rainfall amounts may approach short-duration warning criteria within 15km east of the Main Divide."
A period of heavy rain and possible thunderstorms are also forecast for Fiordland from 4pm to 11pm today,
and amounts may also approach short-duration warning criteria.
Tomorrow, an active front, preceded by strong northwesterlies, was expected to move northeast over the South Island, he said.
"A strong cold southerly follows this front, with snow expected to affect higher roads about the South Island and the central North Island.
"There is a low risk of heavy snow about inland Otago and South Canterbury on Tuesday above 600m.
"The southerly eases over the South Island on Wednesday, then the North Island on Thursday, as a ridge of high pressure moves east over the country."
