Snow has forced the cancellation of some flights in and out of Queenstown Airport through to early afternoon.
Many schools in and around Dunedin are reported to be closed for the day, or had late starts, because of the snow.
Snow in Dunedin has affected both staff and patients trying to reach the hospital.
Southern District Health Board communications spokeswoman Melissa Garry said in a press release an emergency operation centre has been set up.
"Staff are encouraged to make their own way to work if they can safely, however any staff with difficulties getting to work need to call the EOC directly on 03-470-9910 to arrange four-wheel-drive pick up."
She also said patients with appointments at the hospital.
New Zealand Post spokeswoman Clare Pasley said there wouldl be no mail deliveries today in Balclutha, Gore, Queenstown and Dunedin.
Deliveries are underway in Alexandra, Invercargill and Wanaka though there may be some delays.
ROAD CLOSURES/CAUTION REQUIRED:
State Highway 1 between Dunedin to Waitati.
SH 85 Kyeburn To Palmerston
SH 87 Outram To Middlemarch
Strong winds and fallen trees have closed SH6 between Haast and Franz Josef.
The Crown Range road remains closed between Eastburn to Cardrona.
The Queenstown Lakes District Council has alerted drivers watch for black ice.
Other routes around the Wakatipu and Wanaka areas remain open by chains must be carried.
State Highway 6 between Haast to Makarora is closed until further notice.
State Highway 6 Frankton to Kingston is open but caution is needed and chains need to be carried.
State Highway 6 Wanaka to Luggate is open but drivers need to take extreme caution and chains need to be carried.
State Highway 6 Cromwell to Frankton is open but drivers need to take caution.
Frankton to Queenstown is open but drivers required to take extra care.
Makarora to Lake Hawea open buy chains need to be carried.
Kyeburn to Omakau open but drivers need to take caution and carry chains.
Lindis Pass is open but caution needed because of snow and chains to be carried.
Alexandra to Roxburgh caution needed because of snow and chains need to be carried, Kingston to Lumsden open but closed to towing vehicles.
Kingston Rd, Hector Mountains: chains required, closed for heavy trucks
Kawarau Gorge Rd, Waitiri: chains recommended, black ice reported
"Blizzard conditions" are expected across parts of Southland, Otago and the Alpine passes.
Desert Road: Snow, high winds expected. Extreme caution urged