As reported, during the first two weeks of 2014, both currencies are circulated, while the change in all cash transactions is given in euro.
The amount of lats in circulation has been steadily decreasing since the beginning of the year, and the amount of euros in circulation exceeded that of lats for the first time on January 10.
Retailers have also observed that increasingly more customers in stores pay for their purchases using the euro currency.
Lats will be exchanged for euros in commercial banks until end-June, and in regional post offices of Latvijas Pasts postal company in those areas where banking services are not available to local residents – until end-March. At the Bank of Latvia, lats will be exchanged for euros in perpetuity.
Source: The Baltic Course
http://www.baltic-course.com/eng/markets_and_companies/?doc=86228
The euro replaced the lat according to the official exchange rate of EUR 1 per LVL 0.702804 or 70.3 santims.