why does water boil below 100 c at high elevations
High-altitude cooking High-altitude cooking is the opposite of pressure cooking in that the boiling point of water is lower at higher altitudes due to the decreased atmospheric pressure. This may require an increase in cooking times or temperature and alterations of recipe ingredients. For home cooking, this effect becomes relevant at altitudes above approximately 2,000 feet (610 m). At that altitude, water boils at approximately 208°F (98°C) and adjustments sometimes need to be made to compensate for the reduced air pressure/water boiling point.
Boiling Lake The Boiling Lake is situated in the Morne Trois Pitons National Park, Dominica's World Heritage site. It is a flooded fumarole 6.5 miles (10.5 km) east of Roseau. It is filled with bubbling greyish-blue water that is usually enveloped in a cloud of vapour. The lake is approximately 200 feet (61 m) to 250 feet (76 m) across. Dominica's Boiling Lake is the second-largest hot lake in the world. The largest is Frying Pan Lake, located in Waimangu Valley near Rotorua, New Zealand.