Parts of inland Otago and Southland may experience their first frosts of the year over the next two nights, but the MetService says they are not expected to make you wear your socks to bed.
Meteorologist Andy Best said this week began with unsettled weather, caused by a frontal feature zipping up the country, but conditions were expected to settle for many from midweek.
"Forecasters are picking a front to move northeast over the South Island early Tuesday, bringing heavy rain to western parts of the South Island.
"Heavy falls are expected for the Westland Ranges, where a warning is in force.
"Heavy rain watches are also in place for Fiordland, the headwaters of the Otago and Canterbury lakes and rivers, and Buller as well."
Best said the southerlies would die away over the lower South Island today and tomorrow, as a ridge of high pressure moved in from the west.
"This leads to the possibility of light frosts in inland basins of Otago and Southland on Tuesday and Wednesday nights."
"As the ridge of high pressure becomes firmly established across the country from Friday, we are picking fine weather for most places this weekend."