Allegiant carried more than 1.268 million passengers in April 2019, up from 1.154 million in the same period in 218 - representing an increase of 9.9%.
The airline's revenue passenger miles also increased by 10.6% on the same period last year, rising to 1.154 million, up from 1.43 million.
Meanwhile, the airline's load factor decreased year-on-year by 4 percentage points to 81%.
"As stated on our last earnings call, we expected to see pressure on load factor in the month of April due to the significant capacity growth between the end of March and the beginning of the Easter travel period," stated Drew Wells, vice president of revenue and planning. "The decline in April's load factor was not outside of our expectations.