Ryanair said it operated just 600 scheduled flights in April, including a number of rescue and medical flights on behalf of various EU governments, as the coronavirus lockdown closed airspace across Europe.
This compares to 75,501 flights it had been expected to fly before the outbreak of coronavirus.
The airline said its passenger number for April collapsed by 99.6% to 40,000 from 13.5 million the same month last year.
It also said that due to multiple EU government flight bans and restrictions, it expects to carry minimal traffic during the months of May and June as well.
Meanwhile, Wizz Air said that it carried 78,389 passengers in April, down from 3.3 million in the comparative 2019 period, a fall of 97.6%.
But it said its figures will improve this month as it became one of the first European airlines to restart commercial routes from London, Luton and Vienna on 1 May.
The company also said a new airline it is planning to launch with flights between Abu Dhabi in the Middle East and eastern Europe is progressing in line with its initial timeline to start flying this year.
Last week Ryanair said it could take at least two years for passenger demand to return to normal and this could result in up to 3,000 jobs losses, mainly among pilots and cabin crew.
The airline also said it will implement pay cuts of up to 20% as well as the closure of a number of aircraft bases across Europe until traffic recovers.
It added that job cuts and pay cuts will also be extended to the airline's head office and back office teams.
Group CEO Michael O'Leary, whose pay was cut by 50% for April and May, has now agreed to extend this 50% pay cut for the remainder of the financial year to March 2021.
Ryanair said that its first quarter passenger numbers of less than 150,000 passengers will be 99.5% behind its forecast of 42.4 million passengers.
It said that while some return to flight services is expected in the months from July to September, it expects to carry no more than 50% of its original traffic target of 44.6 million in its fiscal second quarter, which is usually its busiest season.