Aurora Energy said customers in Arthur's Point were without power.
A response crew was on the way to investigate the problem.
Meanwhile, the Central Otago District Council said there had been some snow overnight, particularly in the Manuherikia and Maniototo areas. Snow was not lying on the road, but gravel roads were icy as a result.
Danseys Pass Road was closed due to snow and ice.
Road snow warnings are in place for Lewis Pass (State Highway 7), Arthur's Pass (SH73), Porters Pass (SH73), Lindis Pass (SH8), Crown Range Rd and Milford Road (SH94).
MetService meteorologist Andrew James said New Zealand was under a "complicated trough", meaning there would be a lot of cold showers and even snow in parts of the South Island.
"Apart from a couple of fine spells in the upper North Island this afternoon, it is looking like a very cold, showery, unpleasant day for most people."
The wild weather period kicked off yesterday afternoon with a massive tornado that twisted through parts of Ashburton.
James said there had been no more reports of tornadoes overnight, and any more were unlikely today.
Cold southerlies were expected to bring wintry conditions to the south of the South Island through today and into Tuesday.
The complex system would drop temperatures substantially about the country, with heavy rain, and even snow dropping to 400 metres in eastern parts of the South Island, with 30-40cm of snow expected above 800m.
A heavy snow warning was in force for inland Southland, Central Otago and inland Clutha.
Snow had been falling since last night in parts of the South Island, with the Crown Range Rd in Queenstown already with decent cover.
