The currency fell 19 percent in 2018, making it one of the worst performing currencies in Asia, as heavy foreign outflows from government securities weighed on the local currency.
The rupee hit an all-time low of 183.00 against the dollar on Monday, hitting a record low for a seventh straight session, surpassing its previous record of 182.90 marked in the prior session, Refinitiv Eikon data showed.
It has weakened about 5.3 percent since Sri Lanka's political crisis began on Oct. 26. It lost 19 percent in 2018.
The rupee ended at 182.70/90 per dollar, compared with 182.80/183.00 in the previous session. It gained to 181.90 in the early trade, market sources said.
The Colombo stock market was closed on Tuesday for new year. The main index fell 5 percent in 2018.
Foreign investors have been net sellers of 13.3 billion rupees worth of stocks since the political crisis began. The bond market saw outflows of about 67.6 billion rupees ($370.21 million) between Oct. 25 and Dec. 26, central bank data showed.
Last year, there were 22.8 billion rupees of outflows from stocks, while government securities suffered a net 159.8 billion rupees of outflows through Dec. 26, the latest data from the bourse and central bank showed.
President Maithripala Sirisena appointed a cabinet of ministers from his rival party on Dec. 21 after he was forced to reinstate Ranil Wickremeinghe as prime minister, 51 days after he was sacked.
The political crisis is expected to ease, though uneasy relations between the two men could cause fiscal problems, analysts have said. Parliament has approved 1.77 trillion rupees ($9.39 billion) to meet the first four months of expenditures in 2019 and avert a government shutdown from Jan. 1.
Credit agencies Fitch and S&P downgraded Sri Lanka's sovereign rating in early December, citing refinancing risks and an uncertain policy outlook.