It will be the first time this year the freezing level is likely to drop below the mountain top level in the South, weather ambassador Bob McDavitt said.
"It isn't expected to be an unusually cold blast."
A second cold front tomorrow was likely to chill the province further, so that air temperatures in inland Otago would "bottom out" about 3degC-5degC on Saturday morning, he said.
In Dunedin, temperatures were expected to go only as high as 16degC today, 14degC tomorrow and 12degC on Saturday.
Temperatures in inland Otago were expected to be similar or a degree or two higher.
Southwest winds might reach gale force or stronger at times from Otago Peninsula to Stewart Island from today through to Saturday, Mr McDavitt said.
