Beginning on 15 January, all international arrivals to Latvia must present a negative COVID-19 test result or other medical document proving that the person is not infectious.
The certificate must be issued no earlier than 72 hours before!
After arriving to Latvia a ten-day self-isolation is compulsory.
More information:
https://www.mfa.gov.lv/en/consular-information/news/66019-emergency-situation-in-latvia-to-restrict-the-spread-of-covid-19