The DCC said the upgrade is not yet complete but the car park would be reopened in the interim for free all-day parking until further notice.
The decision was made with commuters and Christmas shoppers in mind.
Access will only be available from the St Andrew Street entrance.
Weather dependent, the car park would be closed on December 17 so it could be sealed and then reopened the following day.
"The final stages such as line marking, reinstalling pay and display meters and the shared path will be finished early next year."
The project involves sealing, redesigning and upgrading drainage and creating a 3m-wide shared path along the railway side of the carpark. Safer entrances and exits will be created, using gate barriers to protect pedestrians and cyclists at the St Andrew Street railway crossing.
The upgrade was expected to be completed in April next year.
