The MIlford Road Alliance advised on Saturday that State Highway 94 (Te Anau to Milford Sound) is closed from Hollyford Rd Intersection to Chasm Carpark as heavy rain on snow was expected.
The highway would remain shut overnight and likely until Sunday afternoon or evening.
MetService said an active front was expected to move onto Fiordland from the west on Saturday then move slowly northwards through Westland early on Sunday delivering heavy rain to Fiordland, the Otago headwaters and southern Westland including the Southern Alps.
People were advised to keep up to date with the latest forecasts.