The boiling point of water at sea level at 1 atm pressure is 100^oC.

Pressure on liquids and their boiling points are directly proportional. It means that at higher atmospheric pressure boiling point is more and at low atmospheric pressure boiling point is less. 

This means that water can boil at lower temperatures when it is subjected to lower pressures. Practically, in mountainous regions, where atmospheric pressure is lower, water can boil at temperatures around 95°C or even lower.