Emergency services were busy attending multiple crashes in Clinton, Owaka, Balclutha, Dunedin and Waikouaiti.
''Wet roads and then a late frost meant the roads looked wet but were actually frosty, so a lot of people got caught out,'' Senior Sergeant Dave Scott, of Dunedin, said.
''We were saying to people to leave a bit later for work and be aware that the roads might look just wet but there is black ice everywhere.''
Emergency services attended eight crashes between 8am-9.30am, including a 4WD roll-over on SHI, near Waihola.
Luckily the crashes resulted in only minor injuries, he said.
''It just looks like unfavourable conditions, road crews have been out there throughout the night, but they can't be everywhere at once.''
Police urged motorists to watch their speed and following distances.
There is ice on many roads in the South this morning, including: SH8 - the Lindis Pass; SH6 - Athol-Lumsden; SH97 - Mossburn-Five Rivers.
Roading authorities yesterday warned motorists black ice would be the main concern this morning, after snow made a fleeting appearance in much of the region.
Residents throughout Otago reported snow and sleet showers during the day, along with icy temperatures, but little snow remained by nightfall.
Central Otago District Council roading manager Julie Muir said the wet weather and freezing temperatures were likely to result in widespread black ice overnight and today, so motorists should take extra care.
''It's what we expect in Central Otago this time of year and the grit trucks will be out overnight. We're not panicked about the snowfall, which is fairly light, but drivers should watch out for black ice,'' Ms Muir said.
Snow fell in Queenstown for about an hour yesterday morning before turning to occasional showers. Sergeant Tracy Haggart, of Queenstown, said there had been three weather-related crashes since Tuesday, two resulting in minor injuries.
The Queenstown Lakes District Council reported all roads in its network were open. However, chains had to be carried on the Crown Range road and with snow forecast down to 300m overnight, two trucks were to patrol the road throughout the night.
Glenorchy Hotel manager Tim Brownie said it snowed in the village for about three hours yesterday from late morning.
The weather prompted many tourists to visit Glenorchy instead of going skiing.
''There's lots of Australians in town,'' he said.
Geoffrey Thomson, of Mount Earnslaw Station, said the property had ''got off pretty lightly'' from the cold snap, with only a dusting of snow down to about 2500m on the tops.
However, he had recorded more than 50mm since the weekend.
Snow closed the Lindis Pass road about 5pm yesterday. During the day, snow fell in the mountains around Wanaka but with mainly clear skies over the town.
Although temperatures ranged between 7degC in Oamaru and 3degC at Twizel, with an even lower wind chill factor from a chilly southwest wind, coastal and inland areas of North Otago were without snow yesterday afternoon.
High-country areas of Oamaru and Twizel had no snow at that stage, while Tekapo had patches of a light dusting on surrounding hills.
Ohau Snow Fields and Round Hill ski areas were receiving snow.
Long-time Naseby resident Stuart Hore said the town had a coating of about 2.5cm of snow yesterday - ''barely an inch, so we've got off fairly lightly but we're not complaining''. However, the temperature outdoors was ''struggling'' to stay above zero, he said.
''That must be good news for the [Naseby ice] luge. If they make some snow on the track now, it'll stick around.''
Snow and sleet showers fell throughout Central Otago and the Clutha district in the early afternoon, but apart from a light dusting in the Maniototo, there was no snow lying in the rest of those areas by early evening.
