Sound travels at different speeds depending on the medium it travels through. In air at 20°C (68°F), sound travels about 343 meters per second (m/s), which is approximately 1,235 kilometers per hour (767 miles per hour). The speed is slower in colder air, about 331 m/s at 0°C (32°F). Sound travels much faster in water, around 1,500 m/s, and even faster in solids due to closer molecular spacing. The speed of sound is influenced by temperature, the medium's composition, and density, with sound traveling most slowly in gases, faster in liquids, and fastest in solids.