The first time I saw a visible sign of how heat can affect flying was while boarding a flight in Louisiana: Fog was pouring from the vents inside the cabin. It was pretty alarming, but I eventually realized that the witch’s-cauldron effect was caused by the soupy, humid air seeping in as we boarded mixing with the plane’s ice-cold AC, creating extreme—and very eerie—condensation. Once the cabin’s air temperature and humidity evened out, the fog vanished (as did my worry). It was hot enough that day to make it look like the plane was literally steaming, but we still took off without an issue.
Today, with global temperatures on what seem like a relentless march upward and heat records toppling seemingly every day and everywhere, it raises a bigger question: Is there a point at which it actually gets too hot to fly? My foggy experience is quite common and not a danger for passengers or planes, but could heat cause a serious problem if it gets too steamy outside?
It’s definitely a question you’ll want answered before hopping on a flight this summer. Reader’s Digest asked two Nevada-based experts—Corry Lane, a pilot and the director of safety at Cirrus Aviation Services, and Dan Bubb, a former first officer who piloted commercial planes—to walk us through the highs and lows of flying in extreme heat, and what it means for your safety. Read on to find out the details.
Get Reader’s Digest’s Read Up newsletter for more travel, tech, cleaning, humor and fun facts all week long.
What temperature is too hot for planes to fly?
According to Lane, there is no universal cutoff for when it’s too hot for planes to fly, but performance charts typically max out at around 122 degrees Fahrenheit. “Beyond that temperature, pilots must use manufacturer-specific data, which may include a temperature limit for that particular model,” he explains.
Lane says smaller aircraft are more vulnerable to heat due to their lower thrust-to-weight ratios and limited flexibility for offloading passengers or cargo. For example, in July 2024, Badwater Basin in California’s Death Valley National Park reached a sizzling 128 degrees—so hot that medical helicopters, which are often grounded when the mercury climbs above 120, couldn’t come to the aid of motorcyclists suffering from heat exposure. At such extreme temperatures, it’s not just unsafe for helicopters to take off but also sometimes physically impossible because they can’t generate enough lift.
Larger jets like the Boeing 737 can usually handle higher temperatures pretty well, but as with helicopters, pilots must plan around potential issues with weight and lift. “When I was a pilot [flying out of Las Vegas],” Bubb says, “I had to do calculations to make sure we had enough runway to safely take off. If not, we had to delay or cancel the flight.”
What’s the issue with airplanes and extreme heat?
Aircraft can fly in surprisingly hot weather, but when they do, pilots must meticulously account for one major issue: a condition they call density altitude. “Hot air causes molecules to become excited and spread out, which makes the air less dense,” Lane says. “Less-dense air contains fewer molecules for the wings to generate lift and for engines to compress and combust fuel.”
This means that because of the thinner air, the plane “thinks” it is performing at a higher altitude while it is on the ground, so it will require a longer runway distance to get lift and take off, then also experience reduced climb rates. Why does that matter? “If the planes are too heavy and the runway length is insufficient, pilots will have to reduce the weight,” Bubb says. “That can be done by taking less fuel (which means they will need to stop someplace en route to the destination to refuel), reducing the number of bags or delaying the flight until nighttime, when the temperature is cooler.”
And the type of heat matters too. Dry heat, like you’ll find in the Nevada desert, is a little easier on planes because the lower humidity helps keep the air slightly more dense. On the other hand, humid heat—think Houston in July—adds moisture to the air, which pushes oxygen out. That makes it tougher for even the most sophisticated modern jet engines to burn fuel efficiently and for wings to generate lift. “In extremely hot conditions, engines experience reduced mass airflow, which leads to less thrust,” Lane says of performance degradation, which often becomes noticeable above 95 degrees Fahrenheit. With less thrust, planes take longer to accelerate on the runway and climb after takeoff.
Do airlines schedule afternoon flights in the hottest parts of the country?
Unlike helicopters and some smaller regional jets, large commercial jets continue to take off throughout even the hottest parts of the day, though that could change. “Passengers should expect more climate-adaptive scheduling,” Lane says. He points out that this will be especially true at “hot and high” airports such as Aspen, Denver and Phoenix, where the density altitude issue becomes even more pronounced.
Is it safe to fly when the weather is so hot?
Flying in extreme heat isn’t any less safe than in cooler conditions. It just means that pilots, who are rigorously trained to handle such challenges, need to carefully calculate if they have enough runway to take off, and then plan for slower climbs. “Passengers should not worry about flying in extreme heat,” Bubb says, “but they should understand why pilots don’t load as much fuel or bags or cargo on very hot days.”
While weather-related issues like this are frustrating, passengers should trust that they’re happening for a very good reason: everyone’s safety.
Can extreme heat affect runways too?
It depends. My editor recalls how a friend who was to fly home from Russia years ago couldn’t take off because a severe heat wave caused the runways to literally melt. That was likely due to the materials used in construction. There were also incidents at two U.K. airports in 2022, when unusually extreme heat for the area caused parts of the runways to “lift.”
That said, “unless runways are made of asphalt and it is extremely hot, they will not melt,” says Bubb. He notes that in the U.S., most commercial runways are made of durable concrete that is treated and engineered to withstand high temperatures. “Having flown out of Las Vegas numerous times both as a pilot and passenger, I’ve never experienced a melting runway.”
How can airplanes make things work even in the heat?
In the summer or in warm climates, airlines and private jet operators are hard at work behind the scenes, managing a whole host of heat-related challenges in order to ensure that flights take off and land safely. Here are a few ways they keep flights moving:
Longer runways
“While large jets have more powerful engines, they still face payload restrictions and require longer takeoff rolls in extreme heat,” Lane says. He adds that lengthier runways at hot-weather hubs are necessary, and they’re increasingly being considered as a top development priority everywhere.
Weight limits
Airlines respond to extreme temperatures by lightening aircraft through reducing fuel loads and scheduling of refueling stops mid-route on longer flights. They also may offload cargo, luggage or both to lighten the load. That’s one reason some passengers’ checked bags could get left behind at the airport during heat waves. “It often happens to international flights because those planes tend to be much larger and heavier than other planes,” Bubb says.
Delayed flights
In worst-case scenarios—and a true heat-induced headache for passengers—airlines sometimes must delay flights until temperatures drop. In one rare but particularly extreme instance, passengers on a delayed Delta flight out of Vegas’s Harry Reid International Airport in July 2023 sat on the tarmac in a hot plane for three hours as temperatures climbed well into the triple digits. The situation deteriorated, and the flight was eventually canceled.
Private jets may take similar steps but tend to have more flexibility due to their lower passenger counts and quicker turnaround times.
How are airlines planning for the future as temperatures continue to rise?
Private jet operators and airlines are exploring a range of long-term solutions in response to rising global temperatures. According to Lane, efforts to improve efficiency are especially focused on sustainable aviation fuels and lighter aircraft materials, along with optimized flight paths and advanced engine-cooling systems.
RELATED:
- You Can Now Keep Your Shoes On When Going Through Airport Security—Find Out Which Other Rules Might Be Dropped Next
- Here’s What Would Happen If You Try Opening the Emergency Exit Door Mid-Flight
- Here’s Why Some Flags Are Painted Backward on Airplanes
About the experts
|
Why trust us
Reader’s Digest has published hundreds of travel stories that help readers explore the world safely, easily and affordably. We regularly cover topics such as the best places to visit (and the best times to visit them), tips and tricks to zoom through airport security, flight-attendant secrets, hotel-room hacks and more. We’re committed to producing high-quality content by writers with expertise and experience in their field in consultation with relevant, qualified experts. We rely on reputable primary sources, including government and professional organizations and academic institutions as well as our writers’ personal experiences where appropriate. We verify all facts and data, back them with credible sourcing and revisit them over time to ensure they remain accurate and up to date. Read more about our team, our contributors and our editorial policies.
Sources:
- Corry Lane, director of safety at Cirrus Aviation Services; email interview, July 2025
- Dan Bubb, PhD, former first officer at Air Vegas Airlines, associate professor at the University of Nevada and author of Landing in Las Vegas: Commercial Aviation and the Making of a Tourist City; email interview, July 2025
- KSAT: “Tourists Still Flocking to Death Valley Amid Searing U.S. Heat Wave Blamed for Several Deaths”
- The Atlantic: “A New Danger at America’s National Parks”
- ABC News: “Delta Passengers Fall Sick While Waiting on Vegas Tarmac in Triple-Digit Temperatures”
The post What Temperature Is Too Hot for Planes to Fly? appeared first on Reader's Digest.
from Reader's Digest https://ift.tt/pGZSbde
Comments
Post a Comment