The speed of light is different in different media, including air and vacuum. In a vacuum, such as outer space, light travels at its maximum speed, denoted as "c" and approximately equal to 299,792,458 meters per second.
When light passes through a medium like air, water, or glass, its speed is reduced due to interactions with the atoms or molecules in that medium. The degree to which light is slowed down depends on the optical properties of the medium, including its refractive index. In general, the refractive index of air is very close to 1, which means that the speed of light in air is very close to its speed in a vacuum.
For practical purposes, when light travels through air, the speed reduction is typically negligible, and we can consider the speed of light in air to be approximately the same as its speed in a vacuum. However, if extreme precision is required, such as in certain scientific experiments, the refractive index of air and other environmental factors may be taken into account to determine the precise speed of light in a specific medium.