SAN FRANCISCO (KRON) — Summer travel season is already in full swing with people jetting off to both domestic and international destinations. With Fourth of July around the corner, it’s only going to get busier.

“We have had several days this month with over 68,000 people departing through the security checkpoints in a single day. We think we will hit that number again on Thursday and Friday leading into the July 4th weekend,” said Doug Yakel, SFO Spokesman.

That means being more prepared than ever because this year has been the summer of flight cancellations. Flight Aware said more than twenty thousand flights have been canceled since Memorial Day.

“The industry is down thousands of pilots and thousands of flight attendants so they are working to hire people, but it literally can’t happen fast enough,” said Henry Harteveldt of Atmosphere Research Group.

That coupled with fewer flights, most of which are now fully booked, can be a recipe for disaster, especially over a holiday weekend.

“We are going to a wedding, so we didn’t have much choice what weekend to go,” said Bernie Burke who was traveling to Ireland.

Travel experts said if you haven’t booked your flight yet, it is best to choose a non-stop flight that is the first flight of the day.

If you’ve already booked a flight and that flight is canceled, there are specific steps you should take.

“When you are going to rebook a flight use the app, also message the airline on social media and then get in line at customer service rebooking desk. So, you want to use every tool in your tool belt to try to be the first to get rebooked because remember you are competing against everyone else on that plane who’s flight was canceled,” said Clint Henderson, The Points Guy.

Experts said it’s also a good idea to know what other airlines are flying to your destination in case your flight is canceled. SFO is recommending you arrive two hours early for domestic flights and three hours early for international flights.