Due to multiple factors, expect to potentially pay more when booking in July. For low rates, April can be a great choice for travel to Amarillo. Flights to Amarillo from West Palm Beach in April are about $260 on average during April, but can be found for as low as $101.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from West Palm Beach to Amarillo as you normally would.