The coldest temperatures were all recorded about 8am.
Around Central Otago, temperatures ranging from -7degC to -3degC were reported in parts of the district.
In Dunedin city, residents on their way to work and school faced iced-over windscreens and frosty footpaths as the mercury dipped to -1.8degC about 8am.
MetService meteorologist Lewis Ferris said yesterday's sudden cold snap in the region would not continue throughout the week, and southerners could expect ordinary winter weather for the rest of the week.
Although relatively clear skies were expected through the week, there would be some light rain on Thursday night and again on Saturday afternoon.
''The rain that's going to come across isn't going to be large in amounts, and it's not going to be overly cold for the next few days for the region.
''Everything is normal by standards of winter for the area.''
Dunedin City Council roading engineer Jacob Manson said some gritting was done around the city yesterday on the main arterial roads, including Stuart St, Taieri Rd and Three Mile Hill Rd.
''It wasn't a massive frost, but we put out about 2000 litres of [de-icing agent] CMA.''
Along with the CMA, 18 tonnes of grit were applied to about a dozen affected roads.
Contractors were out every day, starting at 3am, checking the roads for ice and one CMA truck and three gritting trucks were ready to leave first thing in the morning, every morning, should there be a frost.
The council was also offering free windshield ice scrapers at all its service centres.
Scraping windscreens clear was essential and people should remember to allow an extra five or 10 minutes in the mornings to do that so they did not have to rush their road journeys, Mr Manson said.
Police also urged drivers to check road conditions before they got behind the wheel and to take it easy on winter roads.
