Sea-Tac's two hometown airlines, Alaska Airlines and Horizon Air, both saw passenger traffic increases in May, the airlines reported.
Alaska saw its traffic increase by 10.7 percent, while Horizon experienced a 0.4 percent rise.
Both airlines, owned by Alaska Air Group, reported more than 90 percent of their flights were on time last month. Alaska said 91.5 percent of its flights were on time. Horizon said 92.1 percent of its flights arrived on schedule. Both those results are significant improvements over last year.