POST/api/v1/e6b/cloud-base/calculateCommercial Pilot

Calculate Cloud Base

Estimates cloud base height AGL from surface temperature and dewpoint spread.

Code Examples

curl \
  -X POST \
  -H "Ocp-Apim-Subscription-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "temperatureCelsius": 0,
  "dewpointCelsius": 0
}' \
  "https://api.preflightapi.io/api/v1/e6b/cloud-base/calculate"

curl \
  -X POST \
  -H "Ocp-Apim-Subscription-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "temperatureCelsius": 0,
  "dewpointCelsius": 0
}' \
  "https://api.preflightapi.io/api/v1/e6b/cloud-base/calculate"

Description

Uses the standard pilot rule of thumb: cloud base (ft AGL) = (temperature - dewpoint) * 400. This approximates the lifting condensation level based on the average dry adiabatic lapse rate (~3°C/1000 ft) and dewpoint lapse rate (~0.5°C/1000 ft).

Response Fields

EstimatedCloudBaseFtAgl — estimated height of the cloud base above ground level (feet)

TemperatureDewpointSpreadCelsius — the difference between temperature and dewpoint (degrees Celsius)

*Note:* Actual cloud bases vary with humidity profiles, inversions, and local convective conditions. A small spread (less than 3°C) generally indicates a high likelihood of low ceilings or fog.

Request BodyCloudBaseRequestDto

temperatureCelsiusnumber

Surface temperature in degrees Celsius

dewpointCelsiusnumber

Dewpoint temperature in degrees Celsius (must be ≤ temperature)

Response Schema

200Returns the cloud base estimationCloudBaseResponseDto

estimatedCloudBaseFtAglnumber

Estimated cloud base in feet AGL

temperatureDewpointSpreadCelsiusnumber

Temperature/dewpoint spread in degrees Celsius

temperatureCelsiusnumber

Surface temperature used in calculation (°C)

dewpointCelsiusnumber

Dewpoint used in calculation (°C)

400The dewpoint exceeds the temperature, which is physically invalidApiErrorResponse

codestring

Machine-readable error code (e.g., "AIRCRAFT_NOT_FOUND").

messagestring

Human-readable error message suitable for display.

detailsstringnullable

Additional error details (only included in development environment).

servicestringnullable

Name of the external service that failed (only included for 503 errors).

validationErrorsRecord<string, string[]>nullable

Field-level validation errors (only for validation failures).

timestampstring

UTC timestamp when the error occurred.

traceIdstringnullable

Correlation ID for tracing the request.

pathstringnullable

Request path that generated the error.