Boiling point of water in the 50 largest US cities

Why the cities differ

Water boils when its vapor pressure reaches the pressure of the air on it. Carry a pot uphill and less air presses on it, so the water reaches that pressure at a lower temperature. In Colorado Springs the standard atmosphere gives 11.77 psi against 14.70 psi at sea level, and water boils at 201.0 °F.

Only 5 of the 50 stand above 3,000 ft, all in Colorado, New Mexico and Texas: Colorado Springs, Aurora, Denver, Albuquerque and El Paso. Another 7 sit between 1,000 and 3,000 ft. The other 38 lie below 1,000 ft, within 2 °F of sea level’s boiling point.

Your stove may sit higher or lower than the city’s point. Every 500 ft of height moves the boiling point about 0.9 °F, so water in a kitchen 500 ft above the city’s point boils about 0.9 °F cooler. Weather moves it too: a change of 1 inch of mercury on the barometer shifts it about 1.7 °F at sea level.

The formulas

Air pressure, 1976 US Standard Atmosphere [4]

$$p = 101.325\left(\frac{288.15 - 0.0065\,H}{288.15}\right)^{5.255876}\ \text{kPa},\qquad H = \frac{r_0\,z}{r_0 + z}$$

Boiling point, Hyland and Wexler (1983) [5]

$$p_{ws}(T_b) = 1000\,p,\qquad \ln p_{ws} = \frac{C_8}{T} + C_9 + C_{10}T + C_{11}T^2 + C_{12}T^3 + C_{13}\ln T$$

Drinking water, CDC [8]

$$t = 1\ \text{min}\ \ (z \le 6{,}500\ \text{ft}),\qquad t = 3\ \text{min}\ \ (z > 6{,}500\ \text{ft})$$

z is the ground elevation in m, H the geopotential height and r0 = 6,356,766 m; T is in kelvin, p in kPa and p ws in Pa. Hyland and Wexler’s constants over liquid water (ASHRAE 2017, chapter 1, equation 6): C8 = −5.8002206 × 10³, C9 = 1.3914993, C10 = −4.8640239 × 10⁻², C11 = 4.1764768 × 10⁻⁵, C12 = −1.4452093 × 10⁻⁸, C13 = 6.5459673.

Sources

1. U.S. Census Bureau, Population Division (2026). Annual Estimates of the Resident Population for Incorporated Places of 20,000 or More, Ranked by July 1, 2025 Population (SUB-IP-EST2025-ANNRNK), and the dataset sub-est2025.csv. https://www.census.gov/data/tables/time-series/demo/popest/2020s-total-cities-and-towns.html
2. U.S. Geological Survey, National Geospatial Program (2026). Geographic Names Information System, Federal Codes file, FedCodes_AllStates_Text.zip (published 2 September 2026): each city’s populated place and its official location, NAD83. https://prd-tnm.s3.amazonaws.com/StagedProducts/GeographicNames/FederalCodes/FedCodes_AllStates_Text.zip
3. U.S. Geological Survey. Elevation Point Query Service, version 1: ground elevation from the 3D Elevation Program at a point, in feet or meters. https://epqs.nationalmap.gov/v1/docs
4. NOAA, NASA and U.S. Air Force (1976). U.S. Standard Atmosphere, 1976. NASA TM-X-74335. https://ntrs.nasa.gov/citations/19770009539
5. Hyland, R. W., and A. Wexler (1983). Formulations for the thermodynamic properties of the saturated phases of H₂O from 173.15 K to 473.15 K. ASHRAE Transactions 89(2A): 500 to 519. https://www.ashrae.org/technical-resources/ashrae-transactions
6. ASHRAE (2017). ASHRAE Handbook, Fundamentals (SI), chapter 1, Psychrometrics, equations 5 and 6: Hyland and Wexler’s saturation pressure over ice and over liquid water, with the constants C8 to C13 this page prints. https://www.ashrae.org/technical-resources/ashrae-handbook
7. IAPWS (2012). Revised Release on the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam, R7-97(2012), section 8.2, equation 31, the saturation temperature: an independent check, which agrees with this page’s boiling point at every city within 0.001 °C. https://iapws.org/technical-guidance/release/IF97-Rev
8. Centers for Disease Control and Prevention. How to Make Water Safe in an Emergency. https://www.cdc.gov/water-emergency/about/index.html