The latest industry survey conducted by the Irish Hotels Federation reveals that average room occupancy stood at 42% for July, compared with occupancy levels of over 90% for the same month last year.
The IHF said this is the largest year-on-year drop ever recorded by the Irish hotels sector for the peak summer season.
The data shows that bookings for August have also plummeted to levels broadly in line with those in July, while bookings for September show a further dramatic drop in occupancy levels to 24% nationally.
Occupancy rates were lowest in Dublin City and county this month at 17%.
The border region was at 63%, the south east at 63%, the west at 57%, south west at 53%, midlands and mid east at 48% and mid west at 37%.
The survey was carried out at the start of this week and the results are based on the response from 305 properties.
These account for a combined stock of 29,500 guestrooms spread throughout the entire country, making it the largest and most representative survey of its kind to date.
Commenting on the results, IHF President Elaina Fitzgerald Kane said that the figures highlight the requirement for additional sectoral specific measures for tourism.
"Even in a best case scenario we are effectively looking at occupancy levels of less than 30% for the year as a whole. This is nothing short of disastrous for our sector with serious implications for the tourism industry and wider economy," she said.
Ms Fitzgerald Kane said the July stimulus package announced by Government last week, doesn't go far enough to support the sector.
"Unfortunately the stimulus package recently announced by the Government just doesn't go far enough given the scale of the crisis we are facing. The measures fail to deliver the required supports around competitiveness and liquidity, which is very disappointing and could have long-term consequences for tourism and the almost 270,000 livelihoods it supports," she said.