The Las Vegas airport had its busiest month on record in May, with 4.36 million passengers passing through its gates.
The previous single-month record was set last October, when there were 4.34 million passenger arrivals and departures at McCarran International Airport.
In the first five months of the year, 20.2 million passengers passed though the airport, a 3.1 percent increase over the same period last year, according to the Clark County Department of Aviation.
The record-setting month keeps 2018 on track to surpass the record for annual passenger traffic of 48.5 million set in 2017.
Southwest Airlines was the busiest carrier at McCarran, accounting for 1.6 million passenger arrivals and departures.
Spirit Airlines, meanwhile, saw the biggest passenger traffic increase in May, with 361,816 passengers, a 28 percent increase over May 2017.