It’s a hot summer for the Boise Airport — in more ways than one. The airport in May introduced four new daily nonstop flights to and from Seattle, offered by Delta Air Lines. The addition corresponds with a rise in passenger traffic from May 2014. Expect more growth in the next six months, as three airlines — Alaska Airlines, Southwest Airlines and Allegiant — add flights. Allegiant began nonstop service to Los Angeles June 5. Alaska will debut a daily Reno flight in November. And Southwest starts daily nonstop service to Sacramento in January.