Some 12.7m passengers flew on Ryanair routes in August, the airline said today – up 10 per cent from the year before.
Meanwhile, its load factor – how full its planes were – rose to 97 per cent, one percentage point higher than during the same month last year.
The airline's chief marketing officer, Kenny Jacobs, said the rise was thanks to its continued PR drive, dubbed "Always Getting Better".
Last month Ryanair announced a similar rise, with passenger numbers rising to 12.6m, up 11 per cent on the previous July.
Read more: Ryanair boss jets in for crunch Brexit talks
It may be one of the final Augusts Brits can fly with Ryanair: the airline's boss, Michael O'Leary, has been strongly outspoken on the subject, warning of a "real and distinct threat" flights from the UK to the European Union could be grounded after Brexit.
Last month he said the aviation industry had a "hard deadline" of September 2018 for an agreement between the EU and the UK to be reached on the sector.
"September 2018 is when we will start seeing the shit hitting the fan," he said. "Otherwise we will have to start cancelling flights, or taking them off sale."
In a briefing note to transport secretary Chris Grayling, he wrote: "The obvious consequence of any such cessation of all flights between the UK and European Union for a period of time from the end of March 2019 would be deeply damaging for UK tourism, traffic and tens of thousands of jobs at UK airports, within British tourism and the UK economy for as long as such catastrophic disruption would persist."