The Department of Health has confirmed 970 more cases of Covid-19 and 13 further deaths.
The number of people in ICU is 28, down one from yesterday.
There have now been a total of 81,228 confirmed cases of Covid-19 and 2,171 deaths related to the virus in Ireland since the pandemic began.
The Health Protection Surveillance Centre has also denotified nine confirmed cases.
As of 2pm today, 238 Covid-19 patients were hospitalised.
Of today's cases, 470 are men and 494 are women and 64% are under 45 years of age. The median age is 37.
The regional breakdown showed 348 people tested positive in Dublin, with 60 in Limerick, 59 in Cork, 59 in Wexford, 55 in Louth and the remaining 389 cases are spread across 20 other counties.
Commenting on today's figures, Chief Medical Officer Dr Tony Holohan said: "The current trajectory of the disease in the community is of grave concern.
"In the last seven days to midnight Monday, we have reported 4,478 cases, an increase of more than 110% over the preceding week.
"In the last five days, we have seen extraordinary growth in the incidence of the virus across the country, significantly increasing the level of risk associated with the kind of inter-generational mixing that is normally experienced over the Christmas holidays.
"It is up to each one of us to rethink our plans for this Christmas period, especially when it comes to visiting older or more medically vulnerable family members and friends."
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The latest spike in the daily figures comes as the country is to return to Level 5 restrictions with adjustments between 24 December and 12 January.
Taoiseach Micheál Martin said the move was in response to the increase in Covid-19 cases, with a 10% daily growth rate that is "simply not sustainable".
Speaking at Government Buildings, he said that while there is no evidence yet the more virulent strain of the coronavirus is here, "the safest and most responsible thing to do is to proceed on the assumption that it is already here".
The Cabinet agreed that people can travel beyond their county until the end of St Stephen's Day, 26 December.
The changes will allow people after 26 December to stay where they are at that point and travel back to their own home later. However, there will be no new inter-county travel allowed after that date.
Household visits will be reduced to one other household from 27 December. Restaurants and gastro pubs must close at 3pm on Christmas Eve.
The Cabinet also agreed that travel restrictions from Britain to Ireland will remain in place until 31 December.
The ban was initially brought in for 48 hours to safeguard against the appearance of a more contagious form of coronavirus in southeast England.
The ban was due to expire at midnight tonight, but has now been extended.
The HSE has issued updated advice for anyone who has travelled from England, Scotland and Wales since 8 December:
- You should now self-isolate for a period of 14 days from the date of arrival into Ireland, rather than merely restrict your movements.
- You should arrange a Covid test as soon as possible five days after your arrival in Ireland.
- If you develop any symptoms of Covid at any stage, phone your GP and alert them of your recent travel from Great Britain.
- Should your test results be "virus not detected" please continue to self-isolate for the duration of the 14-day period, as you could still be developing symptoms and should protect others from potential risk.
HSE Chief Clinical Officer Dr Colm Henry said: "This is a stricter form of advice than the standard "restrict movements" advice that would otherwise apply to persons travelling to Ireland, but our priorities must be to keep our friends and family safe over Christmas.
"I am asking all those who have travelled to please heed this advice and show this meitheal spirit that we have seen throughout the pandemic."
Meanwhile, Northern Ireland has reported 16 further coronavirus deaths, 12 occurring during past 24 hours, taking official toll to 1,219.
There were also 439 new cases from tests on 2,764 individuals.
The number of confirmed Covid-19 patients in hospital is 447 with 30 in ICU, 23 of whom are on ventilators.
