Milford Highway reopened yesterday for the first time in 12 days, but a decision on whether it stays open will be made today, the New Zealand Transport Agency says.
Area manager Peter Robinson, of Dunedin, said the avalanche risk level had dropped from high to low.
The highway reopened at 9am yesterday.
Rain was expected overnight and today.
How the snow pack above Milford Highway responded, with the rain either setting it off or packing it down, would determine whether the agency kept the road open or closed it again as a precaution.
A small slip of bush and muddy water had been identified among trees above the road, opposite Lake Gunn, 80km north of Te Anau, and it was being monitored, Mr Robinson said.
Rain was likely to trigger the slip, but it was expected to cover only one lane and take half a day to clean up.
