Which factor affects the speed of a wave

Wave involves vibration of particles towards a given direction. Temperature is among the factors that affect the speed of a wave. An increase in temperature of a medium increases the speed of a wave as the vibration of particles increases due to high kinetic energy by the particles thus making the wave move faster.

The speed of a wave is determined by the properties of the medium.

If the wave is a mechanical wave, then its speed is determined by the physical/mechanical properties of the medium ... the density, viscosity, etc.

If the wave is an electromagnetic wave, then its speed is determined by the electrical properties of the medium ... the electrostatic permittivity, magnetic permeability, etc.