There were 640 patients waiting for admission to a hospital bed, according to the Irish Nurses and Midwives Organisation.
University Hospital Limerick was worst affected with 72 patients waiting.
There were 64 patients waiting at Cork University Hospital and 46 at St Vincent's University Hospital in Dublin.
The Health Service Executive TrolleyGar data put the overall national overcrowding figure at 451.
The HSE figures only cover emergency departments.
The peak level of overcrowding was reached on two days in January with 760 patients waiting, according to INMO data.
While influenza activity peaked in late December, it remained above baseline levels in Ireland for the week ending 26 January.
Confirmed influenza hospitalisations are at low levels.
Influenza A (H3N2) has been the dominant circulating virus to date this season, the Health Protection Surveillance Centre has said.
Last week, increases in influenza B activity were observed.
Meanwhile, there has been no confirmed case of the coronavirus here.
IHCA responds to overcrowding figures
The Irish Hospital Consultants Association has said that patients "need access to quality care now" and cannot "wait for the political bargaining of a new government" to be completed.
In a statement, IHCA President, Dr Donal O'Hanlon said: "The delivery of 199 beds was committed to by the end of January to tackle the major overcrowding and bed capacity failings during peak winter illness demand.
"These are not having a sufficient impact, at a time when hundreds more are needed."
Mr O’Hanlon called on all politicians to commit to four key immediate steps:
- Delivery of 800 public hospital beds by end of 2021 and fast-track delivery of 2,600 additional beds by 2025
- End consultant pay discrimination and fill 500 unfilled permanent consultant posts
- Introduce maximum waiting time of four hours for patients presenting at emergency departments, acute medical units or other public hospital units to be admitted, discharged or transferred to more appropriate service
- Introduce maximum waiting time of 18 weeks to see hospital consultant following GP referral for inpatient/day case hospital treatment.