Compute air temperature at any altitude using the International Civil Aviation Organization (ICAO) standard atmosphere or your own custom lapse rate. Visualize the thermal profile with an interactive altitude–temperature graph.
The environmental lapse rate describes how atmospheric temperature changes with increasing altitude. In the troposphere (surface to ~11 km), the average rate is -6.5°C per kilometer under the International Standard Atmosphere (ISA). This phenomenon results from adiabatic cooling of rising air parcels, reduced absorption of terrestrial radiation, and decreasing pressure. The standard model is foundational for aviation performance calculations, weather forecasting, and mountain meteorology.
Standard Lapse Rate Formula (Troposphere):
T(h) = T0 − Γ · h
Where:
T0 = 15°C (sea level temperature)
Γ = 6.5°C/km (lapse rate)
h = altitude (km) above mean sea level.
Above the tropopause (≈11 km), temperature remains nearly constant at -56.5°C in the standard model.
For non‑standard conditions (e.g., temperature inversions, arctic or tropical environments), the custom mode allows you to define your own sea‑level temperature and lapse rate – essential for aircraft takeoff/landing performance calculations, density altitude corrections, and climate research.
At high-altitude airports like La Paz (Bolivia, 4,058 m), standard temperature is about -11°C, but actual hot days can raise density altitude beyond 5,000 m, reducing lift and engine power. Using the custom lapse rate mode, pilots input local sea‑level temperature and observed lapse rate to compute density altitude corrections. Our calculator provides the base atmospheric temperature at any altitude, which is the first step toward accurate density altitude estimation.
On Mount Everest (8,848 m), the standard model predicts ≈ -42.5°C (using 6.5°C/km). However, actual summit temperatures range from -30°C to -45°C depending on season and jet stream activity. Climbers use lapse rate estimates to anticipate gear requirements and hypothermia risks. Our interactive graph helps visualize how quickly temperatures drop — every 1,000 m gain brings a 6.5°C decrease.
Modern wind turbines extend to 150-200 meters hub height. Temperature variations affect air density, directly influencing energy output. Using the custom lapse rate with local meteorological data, site analysts can predict temperature at hub height (often 0.5–1°C cooler than surface) to refine power curves.
| Altitude (m) | Altitude (ft) | ISA Temperature (°C) | Typical Conditions |
|---|---|---|---|
| 0 | 0 | 15.0 | Sea level, mild climate |
| 1,000 | 3,281 | 8.5 | Low mountain/hilly terrain |
| 2,500 | 8,202 | -1.3 | High plateau, freezing possible |
| 4,000 | 13,123 | -11.0 | High altitude settlements (e.g., Cusco) |
| 6,000 | 19,685 | -24.0 | Extreme altitude, summit conditions |
| 11,000 | 36,089 | -56.5 | Tropopause, commercial jet cruise |
| 15,000 | 49,212 | -56.5 | Lower stratosphere (isothermal) |