But don't fret, there are some things you can do — in some cases paying a little extra — to make your trip more pleasant, or to at least buffer the damage if something goes wrong.
— If you miss your connection — or bad weather causes delays — the airlines will automatically rebook you on the next available flight. However, with flights at near capacity, the next open seat could be several days away.
— Don't like the flight you're rebooked on? Get in line to speak to a customer service representative. But also, call the airline directly. If the phone lines are jammed, try the airline's overseas numbers. You'll pay long-distance rates, but might not have to wait. Finally, consider sending a Tweet.
— Consider buying a one-day pass to the airline lounge. For one thing, there are usually free drinks and light snacks. But the real secret to the lounges is that the airline staffs them with some of its best — and friendliest — ticket agents. The lines are shorter and these agents are magically able to find empty seats. One-day passes typically cost $50.
— If you and your loved ones don't have seats together already, and don't want to pay an extra $9 to $99 domestically for a "premium" coach seat, it's very likely that you will sit apart.
— Set up alerts for seat openings. ExpertFlyer.com offers free notifications when a window or aisle seat becomes vacant. For 99 cents, it sends an email if adjacent seats become available.
— Check the airline's website five days before the trip. That's when some elite fliers are upgraded to first class, freeing up their coach seats. Another wave of upgrades occurs every 24 to 48 hours.
— Check in 24 hours in advance, when airlines start releasing more seats. If connecting, check for open seats 24 hours before the second flight departs.
— Keep looking. Even after checking in, seats can be changed at airport kiosks and on some airlines' mobile applications.
— Weigh a bag at home first. Anything over 50 pounds (40 pounds on some airlines like Spirit) will generate a hefty overweight surcharge — typically $100 — in addition to the typical $25 checked bag fee.
— Before your bag disappears behind the ticket counter make sure the airline's tag has your name, flight number and final destination. As a precaution, place a copy of your flight itinerary inside your suitcase with your cellphone number and the name of your hotel.