---
title: "Boiling Point of Water at Altitude Calculator | High Nestle"
description: "Find the temperature water boils at for any altitude or from today's air pressure, using the standard atmosphere and the Antoine equation, steps shown."
url: https://highnestle.top/
---

# Boiling point at altitude

Up high, water boils before it gets to 100 °C (212 °F). Enter your altitude, or a barometer reading, to see the temperature your pot of water really reaches, and how it is worked out.

## Why water boils cooler up high

Water boils when its vapour pressure matches the pressure of the air above it. Climb higher and there is less air above you, so the water boils sooner, at a lower temperature. The USDA puts it at just under 1 °F lower for every 500 feet: about 208 °F at 2,000 feet and 198 °F at 7,500 feet. Anything cooked in boiling water therefore cooks cooler and slower; see [cooking times at altitude](https://highnestle.top/high-altitude-cooking/).

## The method

First, the U.S. Standard Atmosphere 1976 gives the air pressure at your height on an average day. Then the Antoine equation, with the constants the NIST Chemistry WebBook lists for water (Bridgeman and Aldrich, valid from about 71 °C to 100 °C), finds the temperature at which water's vapour pressure equals that pressure. We check it against IAPWS-IF97, the international standard for water and steam; the two agree within 0.05 °C at everyday altitudes, and our results are within 1 °F of the USDA and Colorado State University tables.

## Weather moves the boiling point

Real air pressure rises and falls with the weather, so on a stormy day water boils a little cooler. A weather report's pressure is adjusted to sea level: choose *Weather report* and we scale it to your altitude. A barometer at your location reads the actual pressure, so use *My barometer*.

## Sources

- NOAA, NASA and US Air Force. [U.S. Standard Atmosphere, 1976](https://ntrs.nasa.gov/citations/19770009539). NOAA-S/T 76-1562.
- NIST Chemistry WebBook. [Water: Antoine equation parameters](https://webbook.nist.gov/cgi/cbook.cgi?ID=C7732185&Mask=4&Type=ANTOINE&Plot=on); data from Bridgeman OC, Aldrich EW. Vapor pressure tables for water. *Journal of Heat Transfer* 1964;86(2):279–286. [doi:10.1115/1.3687121](https://doi.org/10.1115/1.3687121)
- IAPWS. [Revised release on the IAPWS Industrial Formulation 1997 for the thermodynamic properties of water and steam](https://iapws.org/technical-guidance/release/IF97-Rev), equations 30 and 31.
- USDA Food Safety and Inspection Service. [High altitude cooking](https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/high-altitude-cooking).
- Colorado State University Extension. [High altitude food preparation](https://routt.extension.colostate.edu/wp-content/uploads/sites/4/2018/05/High-Altitude-Food-Perperation-Guide.pdf) (Table 1). 2013.
- West JB, Lahiri S, Maret KH, Peters RM, Pizzo CJ. Barometric pressures at extreme altitudes on Mt. Everest: physiological significance. *Journal of Applied Physiology* 1983;54(5):1188–1194. [doi:10.1152/jappl.1983.54.5.1188](https://doi.org/10.1152/jappl.1983.54.5.1188)

## More altitude tools

Each runs offline once the page has loaded.

- [Air pressure & oxygen at altitude](https://highnestle.top/air-pressure-oxygen/): Barometric pressure, oxygen partial pressure and effective oxygen %.
- [High-altitude baking adjustments](https://highnestle.top/high-altitude-baking/): Leavening, sugar, liquid, flour, oven and time, from extension tables.
- [Cooking time at altitude](https://highnestle.top/high-altitude-cooking/): Pasta, beans, eggs, pressure cookers and canning above 3,000 feet.

## Recommended

Two free tools for the online side of mountain life: recipes, bookings and shopping.

### A spare inbox for recipe sign-ups

Recipe sites and cookware brands often want an email address before they share a printable or a discount. CleanTempMail gives you an instant disposable inbox, no account needed, and deletes the mail after three days.

[Get a disposable inbox](https://cleantempmail.com/)

### Look before you buy

Ordering a pressure canner or altitude gear from an unfamiliar shop? WebTraceCheck's free domain lookup and website audit help you check the site, and its disposable cloud browser opens doubtful links away from your own computer.

[Check a site with WebTraceCheck](https://webtracecheck.com/)

## Questions

**Can I make the water hotter by boiling it harder?**

No. Turning up the heat only boils the water away faster; it cannot get hotter than its boiling point. Only a pressure cooker raises it.

**Why does my thermometer show a different number?**

Weather changes the pressure, and thermometers vary. Colorado State and New Mexico State extension services suggest testing the temperature of your own boiling water before candy making.

**How hot can water get on top of Everest?**

About 70 °C in the standard atmosphere. Real pressure on the summit is a little higher: in 1983, West and colleagues measured 253 mmHg there, which gives about 72 °C.