What Temperature Does Water Boil? Boiling Point by Altitude
The short answer
At standard sea-level pressure, pure water boils at 212°F (100°C) and freezes at 32°F (0°C) (jump between scales with the °F to °C converter). Boiling happens when water’s vapor pressure equals the surrounding air pressure - so with less atmosphere pushing down at altitude, water boils at a lower temperature. The rule of thumb: subtract about 1.8°F (1°C) per 1,000 feet (300 m) of elevation.
Boiling point by altitude
| Altitude | Boiling point (°F) | Boiling point (°C) | Example location |
|---|---|---|---|
| Sea level | 212°F | 100°C | Miami, New York, London |
| 1,000 ft (305 m) | 210.2°F | 99°C | Dallas, Texas |
| 2,000 ft (610 m) | 208.4°F | 98°C | Tucson, Arizona |
| 3,000 ft (914 m) | 206.6°F | 97°C | Las Vegas, Nevada |
| 5,000 ft (1,524 m) | 203°F | 95°C | Denver, Colorado |
| 7,000 ft (2,134 m) | 199.4°F | 93°C | Flagstaff, Arizona |
| 8,000 ft (2,438 m) | 197.6°F | 92°C | Bogotá, Colombia |
| 10,000 ft (3,048 m) | 194°F | 90°C | Leadville, Colorado |
| 12,000 ft (3,658 m) | 190.4°F | 88°C | La Paz, Bolivia |
| 29,032 ft (8,849 m) | ~160°F | ~71°C | Summit of Mount Everest |
What this means for cooking
In Denver, “boiling” water is only 203°F, so pasta, beans, and eggs cook noticeably slower - A 3-minute egg becomes a 4–5 minute egg.
High-altitude kitchen adjustments
- Add 15–25% to boil times at around 5,000 ft.
- Adjust baking separately - leavening gases expand more in thinner air, so recipes need their own high-altitude tweaks.
- Use a pressure cooker to opt out entirely. It raises the pressure - and therefore the boiling point - back to about 250°F regardless of elevation.
Two related myths: salt added to pasta water raises the boiling point by well under 1°F at normal amounts (it is for flavor, not physics), and cold water does not boil faster than hot water. For the same boiling point expressed in Kelvin and Rankine - alongside other liquids from helium to tungsten - see boiling points across temperature scales.
The kitchen temperature ladder
“Boiling” is just the top rung. Cooks use the whole ladder below it:
| Stage | Temperature | What it looks like |
|---|---|---|
| Warm (proofing yeast) | 95-110°F (35-43°C) | Feels like bath water |
| Poaching | 140-180°F (60-82°C) | Shimmering surface, no bubbles |
| Simmering | 185-205°F (85-96°C) | Small bubbles at the edges |
| Full rolling boil | 212°F (100°C) | Vigorous bubbling that stirring can’t stop |
Superheating: why microwaved water can erupt
In a smooth cup, microwaved water can quietly pass 212°F without a single bubble - there are no rough spots for bubbles to start on. Then a nudge, a spoon, or a coffee granule gives the steam somewhere to form, and the whole cup can flash-boil out of the vessel at once.
Two habits prevent it: leave a wooden stirrer or a non-metallic object in the cup while heating, and pause the microwave partway to stir. The same nucleation physics, run in reverse, is why supercooled water can stay liquid below freezing and then crystallize in a second.