Speeds1 (m/s) of Sound: 1. At 0° C and 1 atm pressure, except where noted.
2. At 20° C and 3.5% salinity.

The speed of sound in air at any temperature T (in °C) can also be found using the equation v = 331 + 0.6*T. For other materials/temperatures/pressures, other writeups in this node describe formulas that can be used to calculate the speed of sound.


Source:
Halliday, Ressnick, Walker. Fundamentals of Physics: Fourth Edition.