Record summer travel for airlines has begun, and so have flight delays.

Air travel is expected to rise in the summer in the United States. The Transportation Security Administration screened a record 2.99 million individuals on Sunday, June 23 — exceeding the record set just weeks earlier on May 24 — and the TSA is anticipating a record holiday period on July 4. TSA expects to screen more than 32 million travelers between Friday, June 28, and Monday, July 8, a 5.4% year-over-year increase in holiday travel.

The record air passenger numbers come amid challenges facing airlines, ranging from supply chain delays to intense regulation, safety crises at Boeing that limit the arrival of new planes to the market, fatigued air traffic controllers, delays due to severe weather, and rising costs that have affected Airlines' bottom lines have compressed margins.

Airports weren't quite ready for the initial summer rush. More than 6,000 flights were delayed Friday evening, May 24, on the East Coast alone. While there may be enough flights to meet demand, record travel still poses challenges for airports, airlines and travelers. For now, airlines are expressing confidence.

Delta Air Lines CEO Ed Bastian told CNBC's “Squawk Box” this week that performance levels are excellent, with “the best first quarter reliability (Delta has) ever had.” (Delta has the best on-time performance record in the U.S.)

But there will also be a need for coordination.

American Airlines CEO Robert Isom told “Squawk Box” that the company makes sure to “operate the most reliable airline possible,” but factors that affect on-time flights range from weather to air traffic control issues.

Air traffic, severe weather

The Federal Aviation Administration has found a shortage of as many as 3,000 needed air traffic controllers. Last summer, a record summer for airports, there were air traffic jams and near-crashes amid challenges in coordinating flights. Based on air traffic patterns and airport density, New York City and Florida have the highest congestion risk.

The extreme heat wave hitting the United States was a glimpse of the kind of extreme weather that could lead to travel problems. The National Oceanic and Atmospheric Administration is forecasting turbulent weather during the holiday week, with storms blowing across the Midwest and East Coast, and dangerous heat persisting in the Southwest and inland Northeast.

Extreme temperatures can cause technical failures that delay flights. The high temperatures create a thin layer of air, which reduces the plane’s thrust to take off and climb. This means planes need a larger runway to take off or a lighter aircraft – by removing luggage or passengers. This means that extremely hot temperatures increase the risk of flight cancellations. Your best bet is to fly early in the morning and late at night.

Good news to reduce travel anxiety

If travelers prepare and have backup plans, they can make the most of the busy summer season. Despite travel anxiety and a host of uncertainties, travel expert and editor-in-chief of The Points Guy, Clint Henderson, says airlines and airports are showing signs of being better prepared than in years past.

Despite the May woes and some airlines pulling back on their overall hiring plans compared to years past, in part because of Boeing delays, Henderson said, “We haven’t seen the major collapses that we saw two years ago. And I think part of the reason for that is the airlines, the airports, everything from Uber to the car rental companies, you know, everybody’s back to work.”

United Airlines expects a 7% increase in passengers starting the week of Independence Day 2023, and is adjusting to new hires. American Airlines flights in the summer are scheduled to increase by 10% year-on-year.

Coordination between air traffic controllers is also witnessing a noticeable improvement. “The federal government and local air traffic control towers have worked better together, and that includes the military,” Henderson says. “They opened up military airspace to help accommodate the crowds, so we've seen extreme congestion. There's still a shortage of air traffic controllers, but that hasn't led to “The worst results we would have expected when we were talking about the shortage of air traffic control personnel even one year ago.”

However, he warns that in severe weather conditions, the lack of air traffic control could exacerbate passenger delays.

Independence Day Travel Tips

With prices lower than expected, many travelers this summer are occasional flyers, who should start by signing up for airline apps that may offer them some introductory benefits, starting with miles and extending to free WiFi on some flights.

Henderson said the easiest ways to save hours of wait time include signing up for programs that give passengers faster movement through security, including TSA PreCheck and Clear, as well as the app-free Mobile Passport Control app, which allows users to fast-track through U.S. Customs.

He also recommends using Flighty, or a similar flight tracking app, to stay informed of options if flight status changes. Travelers also need to stay informed about the routes that the planes they plan to fly on are already flying, to avoid problems at other airports that could ultimately lead to a series of cancellations.

“If your flight is canceled, you’re competing with all those people on that plane to get on the next available flight. So if you have a head start on those people, you’re going to win,” Henderson said. When it comes to peak travel, he said, “information is power.”

Cheap airfares may not be around for long.

Airline ticket prices have fallen, but there are many factors that affect the price, from the traveler's specific destination, with prices varying greatly depending on the route, to how far in advance tickets are purchased, traveling mid-week versus weekend dates, and what the additional fees are. (such as baggage) may significantly raise the total cost of travel.

Moreover, with continuing problems in the supply of new aircraft, from Boeing's production curtailment by the Federal Aviation Administration to Airbus's supply chain stumble, the recent decline in prices may not last long. Henderson expects airlines will eventually raise prices due to increased maintenance costs and reduced fleet capacity.

Labor costs and fuel costs per flight have risen dramatically in the past year. With production delays, airlines are spending billions of dollars to operate less fuel-efficient, more expensive and older aircraft. Technical problems are also more common on older aircraft and are adding to delays.

On June 26, Southwest Airlines lowered its second-quarter revenue forecast while citing booking concerns. The company reported a decrease in expected revenue per seat per mile, and an increase in fuel costs of up to 7.5% year over year.

But for now, even with the higher costs, airfares haven’t returned to their summer 2023 peaks, and consumers are taking advantage. Many last-minute deals from airlines this summer are still available, Henderson said. And even if security lines are long, fares on many routes shouldn’t be too much of a burden for travelers. Hopefully, there won’t be any delays or cancellations.