Calculate lapse rate and temperature shifts across layers. Switch units, compare heights, then export results. Made for quick, clear field decisions in any weather.
Use a consistent atmospheric layer. Real profiles vary by humidity, inversions, and weather.
| Scenario | T₁ | z₁ | T₂ | z₂ | Computed Γ |
|---|---|---|---|---|---|
| Typical troposphere layer | 15 °C | 0 m | 8.5 °C | 1000 m | 6.5 °C/km |
| Cooler upper layer | 10 °C | 500 m | −3 °C | 2500 m | 6.5 °C/km |
| Weak gradient case | 20 °C | 0 m | 18 °C | 1000 m | 2.0 °C/km |
Atmospheric lapse rate describes how air temperature changes with height. Engineers, pilots, and outdoor planners use it to anticipate density changes, icing risk, cloud base tendencies, and performance shifts. A consistent estimate helps convert a temperature observation into a useful vertical profile.
The calculator focuses on the environmental lapse rate derived from measurements or chosen inputs. For comparison, the dry adiabatic rate is about 9.8 °C/km when unsaturated air rises, while moist adiabatic values commonly range from ~4 to 7 °C/km, depending on moisture and temperature.
A widely used reference is the standard tropospheric lapse rate of 6.5 °C/km. In many mid‑latitude conditions, this is a reasonable first estimate for the lowest few kilometers. Your local profile can deviate significantly during fronts, marine layers, or strong mixing. For many applications, a 0–3 km layer assumption gives a practical first estimate when detailed soundings are unavailable.
If you measure 15 °C at 0 m and 8.5 °C at 1000 m, the computed lapse rate is 6.5 °C/km. This mode is ideal for radiosonde snapshots, station pairs, or sensor mast comparisons where you trust both readings.
With a base temperature and a lapse rate, the tool estimates temperature at any altitude using a linear layer model. For example, with T₀ = 20 °C at z₀ = 200 m and Γ = 6.5 °C/km, the temperature at 1500 m drops by about 8.45 °C.
You can invert the same model to find the altitude where a temperature occurs. If T₀ = 18 °C at 0 m and the air reaches 5 °C with Γ = 6.5 °C/km, the estimate is roughly 2000 m above the base.
This calculator reports Γ as positive when temperature decreases with height. It also provides conversions like °F per 1000 ft for aviation-style reporting. Choose output units that match your workflow, then export to CSV for logs or print to PDF for reports.
Real atmospheres are layered. Temperature inversions (warming with height) make Γ negative, while convective mixing can increase variability. For best results, apply the tool over a narrow layer where conditions are roughly linear, and avoid mixing data across different air masses or times.
A common reference is about 6.5 °C per kilometer in the lower troposphere, but real values vary with weather, humidity, and time of day.
A negative lapse rate indicates an inversion where temperature increases with height. It often occurs at night, under high pressure, or near marine layers.
Use “two points” when you have temperatures and altitudes for two locations. Use “temperature at altitude” for forecasting, and “altitude from temperature” to invert the relationship.
No. It models temperature variation with altitude using a linear lapse rate layer. You can use the output temperature as an input to separate density or performance calculations.
Moist air releases latent heat during condensation, reducing the effective cooling rate. That is why moist adiabatic lapse rates are usually smaller than dry adiabatic values.
Enter each input with its own unit selector. The calculator converts internally, then reports results in multiple formats to simplify comparisons and reporting.
Be cautious across strong fronts, deep inversions, or multiple layers. If the profile changes slope with height, compute lapse rate separately for each layer instead.