What factor does the speed of sound vary with?

The speed of sound varies primarily with air temperature due to the way temperature affects the kinetic energy of air molecules. When the temperature increases, the molecules move more quickly, facilitating faster transmission of sound waves through the air. Conversely, at lower temperatures, the air molecules are slower, which reduces the speed at which sound travels.

While altitude, humidity, and pressure can influence the speed of sound to some extent, they are not as directly connected as temperature. At different altitudes, air pressure and temperature decrease, but it is the temperature that governs the molecular motion responsible for sound propagation. Therefore, understanding that temperature is the primary driver of changes in the speed of sound is essential for grasping the associated concepts in acoustics and meteorology.