The road into Milford Sound has been reopened, but the Transport Agency says it will close again on Thursday night.
The road was closed when a landslide brought down tonnes of rocks and debris onto it last Friday.
The agency says workers have cleared a single-lane road alongside the slip, but heavy rain is expected overnight so the road will be closed as a safety precaution from 5pm.
Southland area manager, Peter Robinson, says the lane will also close for three hours from seven in the mornings to allow continuing work.
Further north, on the West Coast, State Highway 73 between Otira and Kumara has been reopened after a washout closed it.