Southland, Central Otago and Clutha motorists are advised to watch for ice and black ice on the roads following overnight rain.
Transit New Zealand has said extreme care is required on SH 6 from Cromwell to Arrowtown, with extensive black ice in the Kawarau Gorge.
The same warning applies to SH 94 from Te Anau to Milford Sound and Mossburn to Te Anau.
