Calculate the atmospheric temperature at any altitude using the standard environmental lapse rate or custom conditions.
Last updated: March 26, 2026 | By ForgeCalc Engineering
Standard tropospheric: 0.0065 °C/m (6.5 °C per 1,000m)
The environmental lapse rate is the rate at which atmospheric temperature decreases with an increase in altitude. In the troposphere (the lowest layer of the atmosphere extending from the surface to about 11km), temperature generally decreases as you ascend because air is primarily heated from the ground up through conduction and convection.
The standard atmospheric lapse rate is approximately 6.5°C per 1,000 meters (or 3.5°F per 1,000 feet) in the troposphere. This rate represents average conditions and can vary significantly based on humidity, weather patterns, time of day, and geographic location. Moist air cools more slowly than dry air as it rises due to latent heat release from condensation.
Understanding the lapse rate is crucial for aviation, meteorology, mountain climbing, and atmospheric science. It helps predict cloud formation altitudes, aircraft performance, weather patterns, and the likelihood of temperature inversions that can trap pollutants near the surface.
Step-by-step guide:
You're planning a hike to a mountain summit at 3,000 meters elevation. The temperature at the base (sea level) is 20°C, and you want to know what temperature to expect at the summit.
At the summit, the expected temperature is approximately 0.5°C (33°F), which is nearly 20 degrees cooler than at sea level. This demonstrates why proper cold-weather gear is essential for mountain activities, even on warm days at lower elevations. Additionally, wind chill at altitude can make it feel even colder.
Air pressure decreases with altitude, causing air to expand and cool (adiabatic cooling). Additionally, the atmosphere is heated primarily from the ground up through radiation and conduction, so regions farther from the surface receive less direct heating.
A temperature inversion occurs when temperature increases with altitude instead of decreasing. This often happens at night when the ground cools rapidly, or when a warm air mass moves over a cold one. Inversions can trap pollutants near the surface.
This provides a good theoretical estimate for the troposphere under average conditions. However, real-world temperatures can vary significantly due to humidity, wind, local geography, time of day, weather systems, and proximity to water bodies.
No. Above the tropopause (about 11km), the temperature trend reverses. In the stratosphere, temperature actually increases with altitude due to ozone absorbing UV radiation. This calculator is only valid for the troposphere.
The dry adiabatic lapse rate (9.8°C/km) applies to unsaturated air. The saturated (moist) adiabatic rate (4-6°C/km) is slower because condensing water vapor releases latent heat, partially offsetting the cooling from expansion.
Pilots use lapse rate calculations to predict aircraft performance, as engine power and lift decrease with altitude. Temperature inversions can create turbulence and affect visibility. Standard atmosphere models use a constant 6.5°C/km lapse rate for flight planning.
Humidity is the primary factor - moist air cools more slowly than dry air due to latent heat release. Other factors include solar heating, surface type (land vs. water), weather systems, and local topography like valleys that can trap cold air.
While this calculator focuses on temperature, atmospheric pressure (which decreases with altitude) determines boiling point. At about 20km altitude, the boiling point of water drops to approximately 20°C, though the air temperature there would be around -55°C.
Related Tools
Calculate ground speed.
Calculate thrust to weight ratio.
Calculate projectile flight time.
Calculate projectile trajectory.
Calculate true airspeed.
Calculate wind correction angle.