As summer temperatures soar, airlines are encountering unexpected hurdles that are reshaping travel plans. While storms and snow are well-known culprits for flight delays, extreme heat is increasingly becoming a significant factor. On the hottest days, the physics of flight are altered, making it harder for aircraft to take off safely. This issue is particularly prevalent in desert regions and high-altitude airports, but even less extreme heat can pose challenges.
In July 2026, American Airlines offered compensation to passengers who voluntarily gave up their seats on a flight from Harry Reid International Airport in Las Vegas, where temperatures reached a scorching 114 degrees Fahrenheit (47 degrees Celsius). This incident highlighted how extreme heat can interfere with air travel, forcing airlines to make difficult decisions to ensure safety.
The Science Behind Heat-Related Flight Disruptions
The primary issue is that hot air is thinner than cool air, which affects an aircraft’s ability to generate lift and thrust. Ross Aimer, a retired United Airlines captain, explains that this is similar to athletes competing at high altitudes, where thinner air can cause fatigue. Jet engines, like human athletes, require cool, dense air to perform optimally.
Before each flight, pilots and airlines calculate several factors to determine if an aircraft can safely take off. These include the airplane’s weight, the airport’s elevation, and the outside temperature. Airports at higher elevations, such as Denver, already operate in thinner air, so even moderate temperature increases can impact takeoff performance. Additionally, shorter runways leave less distance for airliners to build the necessary speed for takeoff, exacerbating the problem.
The Future of Air Travel in a Warming World
Researchers predict that climate change will make heat-related flight disruptions more common. A 2017 study projected that some airports could see weight restrictions on 10% to 30% of flights departing during the hottest part of the day by midcentury if greenhouse gas emissions continue to rise. A more recent study concluded that planes taking off from four European airports would have to shed the weight equivalent of 10 passengers per flight by 2065.
In the United States, the frequency of extremely hot days is increasing. Phoenix Sky Harbor International Airport has averaged 43 days each year since 2026 when temperatures reached at least 110 degrees Fahrenheit (43 degrees Celsius). Harry Reid International Airport in Las Vegas has seen an average of about 18 days a year between 2026 and 2026 with temperatures reaching that threshold, more than double the annual average during the 1940s through the 1960s.
As the planet continues to warm, these challenges are likely to become more frequent and severe. Airlines and airports will need to adapt their operations to ensure safe and efficient travel in a changing climate.
