Different airplanes have a different maximum operating temperature. Bombardier jets, for example, are designed to operate in temperatures of no more than 118 degrees Fahrenheit, whereas larger Airbus and Boeing jets are able to operate in temperatures of no more than about 126 degrees Fahrenheit.

Yes, planes can take off in 110°F (43°C), but it becomes significantly more difficult and less efficient due to the physics of "density altitude." As air gets hotter, it becomes less dense, which means there are fewer air molecules for the wings to push against to create lift and fewer molecules for the engines to "breathe" to create thrust. In 110-degree heat, a plane needs to achieve a much higher ground speed to generate enough lift to get off the runway, which requires a much longer takeoff roll. If the runway isn't long enough, the plane must be lightened by removing passengers, luggage, or fuel—a process known as "weight-shaving." Most modern commercial jets (like the Boeing 737 or Airbus A320) have a "maximum operating temperature" around 122°F to 127°F. When temperatures hit the 110-115 range, airports in hot regions like Phoenix or Dubai often see "payload restrictions." While the plane can safely fly, the airline might have to bump 20 passengers just to make the takeoff mathematically possible on the available pavement.