As an experienced travel writer, I am confidently bringing to you essential insights about your trip from Allentown, Pennsylvania, to Myrtle Beach International Airport via Allegiant Airline - an airline known for its affordable flights and leisure travel. The airline, which prioritizes smaller communities, has been efficiently connecting Allentown to Myrtle Beach for years. This makes it an ideal choice for this itinerary.

Allegiant Airline is a low-cost airline, giving it an edge because cost-saving passengers can travel to their destination without compromising their budget. If you’re leaving from Allentown, you’ll be departing from Lehigh Valley International Airport, which is conveniently located six kilometers northeast of Allentown. Amid the thrill of travel, don't forget the departure time. Allegiant is punctual, and with direct flights to Myrtle Beach, the trip usually takes around two hours.

Upon boarding Allegiant, you'll find that the arrangement of seats allows for cozy and comfortable travel. The airline is known for its service excellence, so expect courteous staff catering to your needs, well-maintained aircraft, and an overall pleasant experience including on-board purchase options to help your journey pass smoothly. Despite being a budget carrier, Allegiant does not compromise on its commitment to safety, which is reassuring.

As you travel south, you’ll be landing at the burgeoning Myrtle Beach International Airport in South Carolina. The airport is not just a gateway to the sparkling sands of one of America's favorite beach destinations – it's also growing to be a hub for shopping and dining, offering several retail outlets and restaurants for travelers to explore.

Myrtle Beach International is designed to keep the convenience of its passengers in mind. The airport is six kilometers southwest of the central business district of Myrtle Beach, making it easily accessible via taxi or ride-share services. Even the parking facilities here are ample and well-organized, which benefits those with rental cars or local friends and family.

Within the airport, the signage is clear and directories are thoughtfully positioned to guide travelers to their desired destinations – whether it's baggage claim, car rental agencies, or refreshment areas. For returning travelers, there's the added advantage of familiar surroundings and workflow.

Regarding the weather, Pennsylvania, being in the north, may have harsh winters which could affect your travel. South Carolina, on the other hand, is known for its subtropical climate. Myrtle Beach can be humid and warm. Therefore, dressing in light, breathable layers is a good idea both for the journey and your destination.

In conclusion, your trip from Allentown to Myrtle Beach via Allegiant is not just about reaching your destination. It's about an affordable yet comfortable flight, about witnessing the efficiency of two thriving airports, and about the joy of knowing everything is well-managed. So be ready – the adventure of travel starts now.