As atmospheric pressure decreases, water boils at lower temperatures. At sea level, water boils at 212 °F. With each 500-feet increase in elevation, the boiling point of water is lowered by just under 1 °F. At 7,500 feet, for example, water boils at about 198 °F.
Is boiling point higher at high altitude?
At a higher elevation, the lower atmospheric pressure means heated water reaches its boiling point more quickly—i.e., at a lower temperature. Water at sea level boils at 212 degrees Fahrenheit; at 5,000 feet above sea level, the boiling point is 203 degrees F.
Why does it take longer for water to boil at higher altitudes?
The key factor is declining air pressure at higher altitudes. Falling air pressure lowers the boiling point of water by just under 1 degree Fahrenheit for each 500 feet of increased elevation. The lower boiling point means water will cook off more quickly, and at a lower temperature.