How does temperature affect air density at altitude?

Higher temperatures decrease air density because warm air expands and occupies a larger volume, which results in fewer air molecules in a given space compared to cooler air. When temperatures rise, the kinetic energy of air molecules increases, causing them to spread apart, thus decreasing the overall density of the air. This relationship is critical for pilots to understand, as lower air density can impact aircraft performance, including lift and engine efficiency.

In contrast, air density is greater in lower temperatures, where air molecules are more closely packed together. Maintaining awareness of temperature effects is essential for flight planning and performance calculations, ensuring pilots can effectively manage the challenges associated with varying atmospheric conditions.