Temperature affects the speed of sound, with warmer air letting vibrations travel slightly faster.

The longer version

Warm air is less dense and its molecules move faster, so a compression is handed along more quickly. The relationship is roughly proportional to the square root of absolute temperature, which means a modest rise on a summer afternoon gives only a small increase in speed.

Humidity matters too, since water vapour is lighter than the nitrogen it displaces. Changing speed bends a wavefront when layers of air differ, and it also shifts the tuning of wind instruments, which players compensate for as a hall warms up. Those instruments depend on the speed of vibration inside their air column.

Where this entry sits

Sound and Music gathers facts about how vibrations move through air and water, how ears turn them into meaning, and how instruments and notation shape what listeners hear. Expect echoes, pitch, volume, acoustics, and the odd silence in between. The full list sits on the Sound and Music page, where every entry is listed in order.