The Tasmania Fire Service's Michael Watkins said smoke and fire were expected to cut off the town's access road at some stage this afternoon.

Mr Watkins said the fire had almost reached backburned containment lines to the west of the township, and firefighters were this morning drawing up contingency plans in case the fire jumped the lines.

It is understood that as many 40 residents left their homes last night, and many had set up camp in a safe zone near the local boat ramp.

Mr Watkins said residents were allowed back to their homes this morning.

He said there had been light rain in the area this morning but firefighters were less than confident that the rain had been enough to stop the fire jumping the containment lines and continue bearing down on the town.