The Department of Infrastructure says bad weather means the Mountain Road won't reopen tonight.
It says work to prepare the route for TT has been delayed because of the wet weather.
The Mountain Road had been due to reopen at 10pm but will remain shut between the Bungalow and Creg Ny Baa overnight.
The DOI says it now hopes to reopen the Mountain at around 4.30pm on Wednesday - but says bad weather may mean more delays.
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