UPDATED 9.25AM: Motorists are being told to brace for snow on state highways throughout the South Island this morning.

PHOTOS: Snowfall in Dunedin

Snow has blanketed Otago and Southland overnight, and MetService has issued a heavy snow warning for Canterbury today.

State Highway 1 is closed between Pine Hill and Waitati, while a truck's blocking State Highway 8 between Tekapo and Fairlie.

Snow has fallen on State Highways 87 and 93, while a slip has reduced State Highway 8 near Milton to one lane.

More snow - update from the #NEV #Dunedin @WeatherWatchNZ pic.twitter.com/AMuhhWmsdh

— Sarah Gallagher (@SarahLibrarina) August 4, 2016

Rockfall warnings are also in place for State Highway 6 near Hawea.

The Crown Range near Queenstown is open and gritted, but more snow is expected.

Motorists passing through Arthur's, Porters, Lewis, and Lindis Passes are being told to carry chains and allow extra time for travelling.

It's been a chilly morning for central Dunedin residents, but those in the hilly suburbs are facing road closures and no public transport.

Snow has blanketed Roslyn, Maori Hill, Brockville and Mornington, while the Peninsula has also been dusted with snow.

Taxis and buses aren't operating in higher suburbs, with black ice and snow too much of a threat.

The majority of schools in Dunedin are having a delayed start, while East Otago and Otago Girls High School are closed.

Patchy snow is expected at the Dunedin and Christchurch airports, but not enough to affect flight times at this stage.

But there may be slight delays on smaller planes leaving Timaru Airport because of snow showers today.

Delays could also hit Queenstown Airport over the weekend, with temperatures set to reach as low as -10 degrees.

Wellington Airport's also expecting gale force south-easterly winds that could affect smaller planes tonight or tomorrow.

http://www.newstalkzb.co.nz/photos/national/photos-snowfall-in-dunedin/