The roads up Mount Canobolas will be closed on Friday afternoon following forecasts of snow.
Cabonne Council announced on Thursday the gates will be shut at 3pm following advice from the State Emergency Service that snowfalls are likely overnight on Friday and early Saturday morning.
The council said boom gates will be closed as a precaution to help ensure motorists are not at risk of an accident or being stranded on the mountain overnight.
Snow is predicted to fall near Orange, Blayney and Oberon and falls are also possible about Lithgow and the Blue Mountains, including the Great Western Highway.
Cabonne Council staff will conduct an inspection on Saturday morning to determine whether the roads can be reopened.
A statement from the council said it would "endeavour to open the roads should conditions allow it", but reminded drivers it was a penalty to ignore road-closed signs.
"However, if snow or ice make conditions dangerous, the boom gates on the access roads will remain closed," it said.
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