The ice road connecting Yellowknife and Dettah via Yellowknife Bay has closed for the season, the Department of Infrastructure said on Thursday.
The department said the road had closed at 10am. It's now illegal to drive on what remains of the ice road until it breaks up.
"Rapidly deteriorating conditions" forced the road's closure, the department said.
The Tłı̨chǫ winter road system will close at 10am on Friday, the department added.
On Tuesday, infrastructure officials said the Tłı̨chǫ roads were now restricted to night travel only.
In both 2016 and 2018, the Dettah ice road made it to April 18 before closing for the season. In 2017, the road closed on April 7 owing to flooding near the shore.
Last year, memorably, an abandoned Buick faced a race against time – and was even ticketed – as it lay on the ice road just days before the expected closure date.