What happens to the air temperature over a runway during a flight?

The air temperature over a runway during a flight reflects the ambient air temperature during flight because it is influenced by the surrounding environmental conditions. As the aircraft takes off or lands, the temperature measured near the runway aligns closely with the overall atmospheric temperature in that area at the time. This ambient air temperature can be affected by several factors, including weather conditions, time of day, and geographic location.

The other options propose potential misconceptions. While aircraft speed can have an effect on other aerodynamic factors, it does not directly alter the air temperature above the runway. The temperature does change with altitude, as it generally decreases as you ascend, thus making the idea of a constant temperature incorrect. Additionally, the notion that the temperature over the runway is always lower than outside air temperature is misleading, as it can vary based on local conditions and may in fact be the same or even higher in certain scenarios, especially during heat waves or in hot climates.