Health officials have announced 6,110 new coronavirus cases and six further deaths.
It takes the death toll in the Republic to 2,265 and the national total number of cases to 107,997.
It is another new record high for the country. The previous high was the 4,962 new cases reported yesterday - by far the highest daily amount Ireland had seen up to then.
The national 14-day incidence rate of the virus in Ireland now stands at 582.8 per 100,000 people.
The seven-day incidence is 443.3 and the five-day moving average is 3,568.
This afternoon, there were 776 COVID-19 patients in Irish hospitals, with 70 people in intensive care.
Meanwhile, more than one-quarter of the 20,571 tests processed yesterday came back positive – up from just over 5% in the days before Christmas.
The Chair of the NPHET Irish Epidemiological Modelling Advisory Group Professor Philip Nolan warned that Ireland could have 1,500-2,000 COVID-19 patients in hospital by mid-January.
He said the same models raise the possibility 200- 400 people could be in intensive care, “if we do not act to radically reduce transmission and incidence.”
“It will take all of us, adopting the public health measures of staying home and reducing contacts, to suppress current levels of disease,” he said.
“Scenario models raise the possibility of 1,500-2,000 people in hospital, and 200-400 people in ICU by mid-January, if we do not act to radically reduce transmission and incidence."@President_MU #COVID19
— Department of Health (@roinnslainte) January 4, 2021
The Chief Medical Officer Dr Tony Holohan called on community leaders and organisations to support those around them to “keep to the spirit of public health advice.”
“We must restrict our movements,” he said. “We have to limit the people we interact with outside of our households if we are to suppress the virus and sustain our essential services.”
He said people who are vulnerable to the virus now need to “stay at home unless absolutely essential.”
He noted that the vulnerable includes: Older persons and people with pre-existing medical conditions including cardiovascular disease, obesity, diabetes, chronic respiratory disease and cancer.
Monaghan has the highest 14-day rate at 1,119.1 per 100,000 people.
Louth is in second with 1,031.2, with Limerick in third at 979, Donegal in fourth at 832.3 and Dublin in fifth with 691.9.
Of the cases announced today, some 3,655 are in Dublin, with 323 in Kildare, 291 in Cork, 234 in Limerick, 137 in Louth and the remaining 1,470 spread across all other counties.