What temperature does water boil at?

By Paulo de VriesLast verified 2026-05-204 sources~6 min readhigh consensus

Water boils at 212°F (100°C) at sea level (1 atm). At higher altitudes, boiling point drops: 5,000 ft = 203°F (95°C), 10,000 ft = 194°F (90°C). Simmer is 180-205°F (82-96°C) — bubbles but not rolling. Pure water + atmospheric pressure determine the exact point.

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The full answer

Water boiling is the most fundamental kitchen temperature, but it varies based on altitude, atmospheric pressure, and what's dissolved in the water. The "212°F = boiling" rule is true ONLY at sea level with pure water and standard atmospheric pressure. Understanding the variables matters for cooking, canning, sterilization, and baking.

**The standard boiling point:**

- **Sea level (0 ft elevation), 1 atm pressure, pure water:** 212°F (100°C) - Defined as: vapor pressure of water = surrounding atmospheric pressure - At this point, liquid → gas transition happens throughout the water (rolling boil)

**The altitude effect (most important variable):**

Atmospheric pressure decreases with altitude. Lower pressure = water needs less heat to boil. Approximation: **boiling point drops ~1°F per 500 ft of altitude gain**.

| Altitude | Boiling point | Common locations | |---|---|---| | 0 ft (sea level) | 212°F (100°C) | NYC, LA, Boston, Miami | | 1,000 ft | 210°F (99°C) | Most US cities | | 2,000 ft | 208°F (98°C) | Salt Lake City foothills | | 3,000 ft | 206°F (97°C) | Albuquerque | | 5,000 ft | 203°F (95°C) | Denver, "Mile High City" | | 7,500 ft | 198°F (92°C) | Aspen, mountain ski towns | | 10,000 ft | 194°F (90°C) | High-altitude hiking | | 14,000 ft | 186°F (86°C) | Mt. Whitney summit | | 29,000 ft | 158°F (70°C) | Everest summit |

**What this means for cooking:**

At high altitudes, water boils at lower temperatures, so foods take longer to cook. At 5,000 ft (Denver): - Pasta: 1-2 minutes longer to al dente - Hard-boiled eggs: 12-14 min instead of 10 - Rice: needs more water, longer time, or pressure cooker - Boiling meat / blanching vegetables: noticeably longer - Canning: requires longer processing time or higher temperatures

At 7,500 ft+, baking also changes (lower air pressure affects rising — but that's separate from boiling).

**Pressure effect (pressure cookers):**

Pressure cookers raise the boiling point by trapping steam: - 15 psi pressure: water boils at **250°F (121°C)** - 10 psi: 240°F (115°C) - 5 psi: 227°F (108°C) - This is why pressure cookers cook 2-3× faster than regular pots

Conversely, vacuum chambers (sous vide circulators that pull vacuum) drop boiling points dramatically.

**Dissolved solutes effect:**

- **Salt:** 1 tsp salt per quart raises boiling point ~0.3°F — negligible for cooking - **Sugar:** 1 cup sugar per quart raises boiling point 1-2°F — noticeable in candy-making - **Heavy syrup at 220°F (sea level)** = 6°F above water boiling = sugar concentration ~50% by weight - This is why candy-making relies on temperature, not time

**Simmer vs. boil (the chef distinction):**

- **Hard rolling boil:** 212°F (sea level), continuous large bubbles bursting at surface - **Boil:** 212°F, bubbles continuously at surface - **Simmer:** 180-205°F (82-96°C), small bubbles, gentle motion - **Bare simmer (poach):** 160-180°F (71-82°C), barely moving, isolated bubbles - **Poach (eggs):** 180-190°F (82-88°C), no bubbles to surface, very gentle motion

**Why simmer not boil for stocks:**

A rolling boil at 212°F: - Emulsifies fat into water (cloudy stock) - Breaks down delicate proteins - Can make meat tough (denaturing proteins quickly) - Loses delicate flavors via faster evaporation

Simmer at 180-200°F: - Fat stays separate (skimmable for clear stock) - Proteins denature gently - Meat tenderizes vs. toughens - Delicate flavors preserved

**Temperature ranges for water-based cooking:**

| Method | Temperature | Application | |---|---|---| | Rolling boil | 212°F | Pasta, blanching, canning | | Boil | 200-212°F | Steam vegetables, vigorous reduction | | Hot simmer | 195-205°F | Stews, braises, slow reduction | | Simmer | 180-195°F | Stocks, broths, poaching meat | | Hot poach | 170-180°F | Delicate fish, custard cooking | | Cold poach | 150-170°F | Eggs, delicate proteins | | Sous vide | 120-185°F | Precision cooking | | Warm hold | 130-150°F | Food safety zone for holding |

**Boiling point of other common liquids (cooking reference):**

| Liquid | Boiling point | |---|---| | Water | 212°F (100°C) | | Milk | ~212°F (proteins scald at 180°F+) | | Heavy cream | ~218°F (slightly higher than water) | | Wine | 173-175°F (alcohol boils off at 173°F) | | Beer | ~170°F (alcohol component) | | Pure ethanol | 173°F (78°C) | | Olive oil | 570°F (300°C) — see deep frying | | Maple syrup (at consistency point) | 219°F (104°C) at sea level | | Honey | varies widely — 220-235°F |

**Common altitude-cooking adjustments:**

- **Boiling water for pasta at 5,000 ft:** add 1-2 min cooking time - **Eggs at altitude:** 12-14 min for hard boiled (vs. 9-10 sea level) - **Rice cooker at altitude:** add extra water, extra time, or use pressure cooker - **Canning at altitude:** longer processing time per USDA charts (essential for safety) - **Boiled potatoes:** noticeably longer at altitude

**Don't:** - Assume water boils at 212°F regardless of location - Confuse "rolling boil" with "simmer" for delicate cooking - Cook meat at rolling boil (toughens proteins) - Use less time for high-altitude boiling (food won't be safe or cooked through) - Try to "boil away" alcohol completely (some alcohol can persist even with long simmering)

**Common mistakes:**

- **High altitude under-cooking:** assume sea-level times; food undercooked - **Stock turning cloudy:** boiled too vigorously instead of simmering - **Watery sauce:** confused simmer (200°F) with boil (212°F), didn't reduce - **Tough meat in soup:** rolling boil instead of gentle simmer

**Cross-reference:** see /pages/how-to-convert/celsius-to-fahrenheit for temperature conversions + /pages/what-temperature-for/cooking-chicken for cooking temperatures + /pages/how-long-does/cooking-rice for altitude-affected timing.

Most published references (NIST Chemistry WebBook, Harold McGee "On Food and Cooking", USDA canning guides, Modernist Cuisine, J. Kenji López-Alt "The Food Lab") converge on 212°F sea-level baseline with altitude/pressure/solute variations as documented above.

Time ranges by condition

Condition	Duration	Note
Sea level (standard)	212°F (100°C)	—
Denver / 5,000 ft	203°F (95°C)	—
10,000 ft	194°F (90°C)	—
Pressure cooker (15 psi)	250°F (121°C)	—
Simmer	180-205°F (82-96°C)	—
Bare simmer / poach	160-180°F (71-82°C)	—

What changes the time

Altitude. Boiling point drops ~1°F per 500 ft elevation gain
Atmospheric pressure. Lower pressure = lower boiling point (vice versa for pressure cookers)
Dissolved solutes. Salt: negligible effect; sugar: 1-2°F rise per cup per quart (matters in candy)
Boil intensity. Rolling boil (212°F) vs. simmer (180-200°F) — choose based on what you're cooking
Pressure cooker setting. 15 psi = 250°F; 10 psi = 240°F; 5 psi = 227°F

Common questions

Why does water boil at a lower temperature at high altitude?

Atmospheric pressure decreases with altitude. At sea level, atmospheric pressure (~14.7 psi) pushes down on water — water needs to reach 212°F before vapor pressure overcomes that. At 10,000 ft, atmospheric pressure is only ~10 psi, so water needs less heat (only ~194°F) to overcome it. Less pressure = lower boiling point.

What is the difference between simmer and boil?

A boil is 212°F (sea level) with continuous large bubbles bursting at the surface. A simmer is 180-205°F (82-96°C) with small bubbles and gentle motion — much less vigorous. Simmering is gentler on delicate ingredients (stocks, custards, meat). Boiling is for pasta, blanching, and aggressive reduction. The difference matters for texture and clarity.

Does salt make water boil faster?

No — counterintuitively, salt slightly raises water's boiling point (the salt increases boiling temperature by ~0.3°F per teaspoon per quart). However, salty water takes ever-so-slightly longer to reach boiling. The main benefit of salting pasta water is flavor, not boiling speed. The "salt boils water faster" myth is wrong; cooking time changes are negligible.

Sources

We cite primary research, expert practice, and authoritative reference. Higher-tier sources weighted heavier. See methodology.

Tier 1 · peer-reviewed / governmentalTier 2 · editorial referenceTier 3 · named practitioner

T1NIST Chemistry WebBook (Water Properties) — Official US scientific reference for boiling points at varied conditions
T3Harold McGee, "On Food and Cooking" — Scientific framework for water-based cooking and altitude effects
T1USDA Complete Guide to Home Canning — Altitude-adjusted processing times for safe canning
T3J. Kenji López-Alt, "The Food Lab" — Simmer vs. boil + altitude cooking practical guide

Why this page existsThis page exists because “What temperature does water boil at?” is one of the recurring questions we measure across search queries + LLM crawls + reading depth. When enough asking accumulated, we wrote this answer with sources cited. The mechanism is the trust signal — see how it works.

What could change this answer

honest uncertainty

We don’t know your specific equipment, ingredient batch, or environment. This answer is the best directional estimate from cited sources. Here’s where it’s less certain:

5 factors shift the answer. Your specific altitude, atmospheric pressure, dissolved solutes (and more) can move this estimate in either direction. The table below shows the documented ranges.
Range spans 6 documented conditions. Pick the row that matches your scenario; halfway between two rows is your best estimate. The widest condition you can imagine is the safer upper bound.
Treat as a directional starting point. Real-world equipment, ingredient batch, and ambient conditions cause natural variance the table cannot capture. Use sensory checks (sight, smell, touch, internal temperature when relevant) alongside this answer — not instead of it.
Backed by 4 cited sources — verify if precision matters. See the Sources section for primary references. Cross-check the cited materials when stakes are high: commercial production, food safety, allergens, dietary or medical considerations.
Verified yesterday. If you found a better-sourced answer or our answer no longer matches reality, tell us — corrections are public and dated. The page exists to be accurate, not to be unchanged.

Cite this page

de Vries, P. (2026). What temperature does water boil at?. AskedWell. Retrieved 2026-05-21, from https://askedwell.com/pages/what-temperature-for/water-boiling

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Last verified: 2026-05-20 · Published 2026-05-20

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