Ryanair's passenger numbers for September were 64% lower when compared to the same month of 2019.
The airline carried 5.1m people during the month, compared to 14.1m in September of last year.
The September figure is also 2.1m lower than the number for August, when passenger numbers were down 53%.
Ryanair said it operated around 53% of its normal schedule in September, filling around 71% of the seats it offered.
Yesterday Ryanair warned it would close its bases in Cork and Shannon at the end of the month, unless the Government here adopted the European Union's traffic light travel system by the 13 October.