Travelers and airlines are bracing for a chaotic July 4 weekend. Here's what to do if your flight is canceled or delayed.

• US airlines canceled over 900 flights on Wednesday and Thursday ahead of the July 4 weekend.
• Airlines have taken action to prevent disruptions, like starting boarding earlier or bringing in extra workers.

Travelers may be in for a hectic Fourth of July weekend.

In the days leading up to the long holiday, airlines have already started canceling and delaying flights. On Wednesday, United Airlines and American Airlines both delayed over 20% of their scheduled flights and canceled 103 and 277 others, respectively, according to FlightAware data.

Delta Air Lines was not much better, delaying 538 flights, or 18% of its schedule, and canceling 65.

The three mainline carriers continued the trend into Thursday, having canceled over 250 flights, per FlightAware. Over 5,500 flights total were delayed or canceled by all airlines operating to, from, or within the US.

Another 350 have been canceled or delayed by American, Delta, and United on Friday, as of the time of publication, according to FlightAware.

The disruptions come as booming demand and staffing shortages create chaos for airlines and passengers, especially over key holiday weekends. Over the Juneteenth weekend, more than 35,000 flights were canceled or delayed from Thursday to Monday, while 4,500 were canceled over Memorial Day weekend in May.

With travelers getting nervous ahead of the likely hectic weekend, airlines are making efforts to keep their flights on schedule, like cutting departures, bringing in more workers, and starting boarding earlier.

Delta Air Lines CEO Ed Bastian said in a message on Thursday that the airline deployed its "Peach Corps" program for the Fourth of July weekend, meaning the company has sent corporate workers to assist at its Atlanta and New York airports, like checking in passengers and helping with bag drop, among other duties.

Moreover, the carrier is offering a fare difference waiver for travelers who want to change their flights over the weekend.

United has opted to slash 12% of its daily departures out of its busy Newark Liberty International Airport hub, which is the second-most delayed airport in the nation, CNBC reported. The company says the move will improve on-time performance and make flying through Newark easier for all travelers.

The Chicago-based carrier told Insider that it anticipates 5.2 million customers to fly United over the Independence Day weekend, which is 24% higher than in 2021 and about 92% of what they saw in 2019.

Despite the airline's best efforts, many travelers are going to face challenges at the airport regardless of how well they prepare. Here are six things to do if your flight gets canceled or delayed.

Know the ways to contact your airline

Airline customer service can be reached via phone or by talking to agents at the airport. However, some airlines have a dedicated center in the terminal where everyone must go to get help, but those lines can be very long.

If you prefer to call instead, here are the customer service numbers for US carriers:

• Alaska: 1-800-252-7522
• Allegiant: 1-702-505-8888
• American: 1-800-433-7300
• Avelo: 1-346-616-9500
• Breeze: No phone number. The fastest way to contact Breeze is via Facebook Messenger.
• Delta: 1-800-221-1212
• Frontier: 1-801-401-9000
• JetBlue: 1-800-538-2583
• Southwest: 1-800-435-9792
• Spirit: 1-855-728-3555
• Sun Country: 1-651-905-2737
• United: 1-800-864-8331

While you wait for a representative to answer, which has taken up to four hours for some customers, try reaching out to companies via social media, like Twitter.

Sending a direct message early on can act as a virtual placeholder, and you may hear back via a chat before you talk to a live human. However, this method is not fool-proof and is best to be used in conjunction with other lines of communication.

Know how the airline is preparing for inclement weather

If you travel this summer, it is almost guaranteed you'll experience some type of weather event. Thunderstorms and hurricanes are common across the US and can cause significant delays and cancellations, which are out of the airline's control.

If there is impending weather then carriers known will disrupt operations, they will typically send an email or text message to customers, or publish a warning on their website. For example, Frontier Airlines waived change fees for passengers scheduled to travel during a tropical storm that moved across Florida in early June.

Rebook flights on an airline's website or mobile app

When flights get delayed or canceled, there is typically a rush of people eager to talk to a customer service agent at the airport. However, it is easier and faster to make changes on the carrier's website or mobile app. In most cases, flight changes should be free, or you can request a refund.

During high-traffic situations where thousands of people are making changes at once, it is possible that all of the options will be taken. So, act quickly, or you may need to seek out a customer service agent as your plan B.

Know your traveler rights

If your flight is canceled altogether, airlines must offer customers a refund, according to the Department of Transportation. In other cases, like a voluntary cancelation, airlines may offer credits that can be used at a later date.

Refunds, however, give more freedom to the customer to rebook a flight on a different carrier.

If you find yourself stranded at an airport due to a delay or cancelation caused by the airline, like crew staffing, then you can ask for a meal or hotel voucher.

Airlines, however, are not obligated to give passengers anything when things outside of their control, like weather, cause disruptions.

Moreover, DoT laws do not require them to compensate customers for delays. In these cases, you should be familiar with your airline's reimbursement policies, and always ask for a meal voucher regardless of the reason for the delay — it never hurts to ask.

Know what your travel credit card or trip insurance policy covers

High-dollar credit cards like the Chase Sapphire Reserve and American Express Platinum Card have built-in trip insurance when you make any travel-related purchases with those cards.

There are also travel insurance companies, like Allianz, that cover costs lost by disruptions. For example, if you don't make it to your final destination for at least 24 hours "due to severe weather (or another covered reason)," then Allianz has a coverage plan.

Allianz's 24-hour policy is not always the case. Chase's "trip delay reimbursement" policy reimburses customers for 6-hour delays or overnight stays.

Insider used Chase's reimbursement benefit on a trip in summer 2021 and was covered for all expenses.

Get ready for long lines, but know when enough is enough

During the busy summer travel season, understand that airlines will be rebooking thousands of passengers and long lines will form. Expect to wait on hold with customer service agents for hours, and be ready to wait for a response via social media.

Give yourself a cut-off time that you will wait for your flight or an agent. Once that passes, start looking at other options to get to your destination, like driving or taking a train. In many cases, these expenses are covered by trip insurance.