There were 1,215 new confirmed cases of coronavirus in Uruguay on Sunday, a new record for the nation of 3.4m people.
The figure is 28% higher than the previous daily record on 6 January.
Uruguay, which had a very low number of infections early on and had been praised by global health officials for its handling of the pandemic, has seen cases rise steeply since December.
There are currently almost 7,000 active cases, more than at any other time during the pandemic.
Montevideo is the worst affected province with more than 4,000 active cases.
Due to the rise in new cases, the government announced last week that it would extend its border closure by 20 days to 30 January.
However, some theatres will be allowed to reopen from Monday to smaller audiences.
Bars and restaurants will also be allowed to stay open two more hours per day. President Luis Lacalle Pou explained the decision by saying "that almost all the infections had been within families".
Heath officials in the capital, Montevideo, are worried cases there may rise rapidly in the coming weeks as holiday-makers return from the country's beaches after their New Year's break.
He urged young people in particular to self-isolate at the first signs of symptoms because of the threat of contagion they may pose to elderly relatives.
While there is concern in Uruguay about this latest spike, the country's cases per 100,000 inhabitants are well below those of its neighbours Brazil and Argentina, which are five times higher than those of Uruguay, according to a tally kept by Johns Hopkins University (JHU).
Overall, there have been more than 26,000 cases in the country and 256 deaths from the virus, according to JHU figures.