State Highway 73 in Canterbury has closed due to snowfall and snow is forecast for much of Te Waipounamu tonight, with close to 10 centimetres expected on some major roads.
Waka Kotahi says State Highway 73 - Arthur's Pass - will remain closed overnight between Castle Hill and Springfield.
Chains are essential for the sections of the road that remain open.
Waka Kotahi said with no detour route available, people should postpone travel.
MetService has issued a severe weather warning of heavy snow for the south and east of the South Island.
Its road snowfall warning covers Lewis Pass (SH7), Arthur's Pass, and Porters Pass from Sunday evening until late Monday. Heavy snow of up to 40cm in some cases is expected, and some further snow is expected on Tuesday morning.
There is also a heavy snow warning for Marlborough south of Ward from 1am to 5pm Monday, with between 10 and 20cm of snow expected above 400m, with some disruptive snow below that level.
Inland Canterbury also has a heave snow warning at elevations above 300m until 2pm Monday with up to 25cm of snow expected.
Earlier today, river levels in Canterbury were dropping after days of heavy rain sparked flooding warnings across the region.
The Canterbury Regional Council said all rivers impacted by rain had peaked in the upper reaches, although some rivers remained high in lower reaches today.
Property owners near the Lower Waitaki River were being urged to monitor the situation as high flows could run onto neighbouring farmland.
Excess flows of up to 1100 cumecs are expected to come over the Waitaki dam.
RNZ
