Temperature drops as altitude increases, at a fairly predictable rate: roughly 3°C (5.4°F) for every 1,000 feet you climb. This holds true through the troposphere, the lowest layer of Earth’s atmosphere where all our weather happens. But the pattern reverses in higher atmospheric layers, and certain weather conditions can flip it near the ground too.
Why Air Gets Colder as You Go Up
The cooling isn’t simply because you’re “farther from the sun.” The sun is 93 million miles away, so a few thousand feet makes no difference. The real reason is air pressure. As you gain altitude, the atmosphere above you has less mass pressing down, so air pressure drops. When air pressure drops, air expands. That expansion forces air molecules to spread out and slow down, which lowers their temperature.
This process is called adiabatic cooling. The air does work on its surroundings as it expands but doesn’t absorb heat to compensate, because air is a poor conductor of heat. So its internal energy drops, and it gets colder. It’s the same principle that makes compressed air feel cold when you release it from a canister.
How Fast Temperature Falls With Altitude
The rate of cooling depends on whether the air contains moisture that’s condensing into clouds or rain. Dry air cools at about 3°C per 1,000 feet of elevation gain (roughly 9.8°C per 1,000 meters). This is called the dry adiabatic lapse rate, and it’s essentially constant.
Saturated air, meaning air where water vapor is actively condensing, cools more slowly: about 1.5°C per 1,000 feet at low altitudes in warm regions. The reason is that when water vapor condenses into droplets, it releases stored heat energy back into the surrounding air. This offsets some of the cooling from expansion. At higher altitudes and latitudes, where the air holds less moisture, saturated air cools closer to the dry rate of 3°C per 1,000 feet.
In practice, the actual cooling rate on any given day (the environmental lapse rate) varies with weather conditions, humidity, and geography. But the standard average of about 2°C per 1,000 feet (6.5°C per 1,000 meters) is a reliable rule of thumb for the troposphere.
When Temperature Actually Rises With Altitude
The troposphere extends roughly 7 to 12 miles above the surface, depending on latitude. Above it, the pattern reverses. In the stratosphere, temperature increases with altitude because the ozone layer sits there, absorbing most of the sun’s ultraviolet radiation and converting it to heat. Temperatures climb from around -55°C at the base of the stratosphere to near 0°C at its top.
Even within the troposphere, temperature sometimes increases with altitude in what’s called a temperature inversion. The most common type is a radiational inversion, which forms on clear, calm nights when the ground radiates heat rapidly and chills the air directly above it while warmer air sits higher up. Cold water bodies can produce the same effect: in early summer, the Great Lakes chill the air just above their still-cold surfaces, creating a warm layer above a cold one. Shallow cold fronts, where a thin wedge of polar air slides under warmer air, also generate inversions.
Inversions trap pollutants and fog near the surface, which is why cities in valleys or near coastlines sometimes experience persistent smog during calm weather.
What This Means at High Elevations
The temperature drop is significant for anyone heading into the mountains. If it’s 20°C (68°F) at the trailhead and you climb 5,000 feet, expect temperatures around 10°C (50°F) at the top, even on the same sunny day. At 10,000 feet above your starting point, you’d be near freezing. Wind chill, which increases with altitude due to less sheltering terrain, makes it feel even colder.
High-altitude locations also experience wider swings between daytime and nighttime temperatures. Research from weather stations across elevated regions found that this daily temperature range increases by roughly 1.25°C for every 1,000 meters of elevation in open terrain. Thinner air holds less heat, so mountaintops warm quickly under direct sun and cool rapidly after sunset. A comfortable afternoon can turn dangerously cold within hours of darkness.
Effects on Cooking and Boiling Water
Lower air pressure at altitude doesn’t just cool the air. It also lowers the boiling point of water, which has practical consequences for cooking. At sea level, water boils at 212°F (100°C). At 5,000 feet, it boils at 203°F. At 10,000 feet, it boils at just 193.6°F.
Because the water is boiling at a lower temperature, it’s less effective at cooking food. Pasta, rice, beans, and eggs all take longer to prepare at high altitude. Baking is affected too, since moisture evaporates faster from doughs and batters. If you’ve ever noticed “high altitude instructions” on a box of cake mix, this is why: the recipe needs adjustments to compensate for the lower boiling point and faster evaporation.
The Bigger Picture Across the Atmosphere
Earth’s atmosphere has four main temperature layers, and the pattern alternates. The troposphere (surface to about 7-12 miles) gets colder with altitude. The stratosphere (up to about 31 miles) warms with altitude thanks to ozone absorbing UV radiation. The mesosphere (up to about 53 miles) cools again, reaching the coldest temperatures in the entire atmosphere, around -90°C. The thermosphere (above 53 miles) heats up dramatically as gas molecules absorb high-energy solar radiation, with temperatures that can exceed 1,000°C, though the air is so thin it wouldn’t feel hot.
For most everyday purposes, the troposphere is what matters. If you’re hiking, flying, farming at elevation, or just wondering why mountaintops are snow-covered in summer, the answer comes back to the same principle: rising air expands under lower pressure, and expanding air cools at a steady, predictable rate.