Lang Rain Factor Calculator
Lang annual P/T rain factor with strictly positive annual mean temperature in Celsius. Distinct from De Martonne P/(T+10) and P/PET. Caller verifies normal coverage and applicability; not a drought category or crop suitability assessment.
Description
Lang's rain factor divides annual precipitation by a positive mean temperature.
Lang's rain factor divides annual precipitation by a positive mean temperature.1
Its unit-dependent ratio should not be read as a calibrated drought probability. Use Lang Rain Factor Calculator to evaluate the supplied inputs under the model explained below.
When to use Lang Rain Factor Calculator
Use Lang Rain Factor Calculator to evaluate the supplied inputs under the model explained below. Establish the units, measurement scope and model assumptions before entering values.
How to use Lang Rain Factor Calculator and understand its results
- Establish the units, measurement scope and model assumptions before entering values.
- Enter Annual precipitation mm, Annual mean temperature c using the field table and validation rules below, then run the tool.
- Read Lang annual rain factor; interpret the units, signs, ordering and unknown-value placeholders described below.
- Correct reported input errors and rerun. Apply successful results according to their specific meanings and check the assumptions before using them in a decision.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| annualPrecipitationMm | Annual precipitation mm | number | Required; constraints below |
| annualMeanTemperatureC | Annual mean temperature c | number | Required; constraints below |
Enter nonnegative annual precipitation in mm and a strictly positive annual mean temperature in °C. Divide precipitation by temperature. Zero rain returns zero, and nonpositive temperature is rejected rather than generating an alternate cold-climate convention. No categorical humidity thresholds are installed.
LangFactor=annualPrecipitationMm/annualMeanTemperatureC Use the field order, units and branch conditions described above.
| Output field | Meaning | Value type |
|---|---|---|
| langAnnualRainFactor | Lang annual rain factor | number |
{
"input": {
"annualPrecipitationMm": 1000,
"annualMeanTemperatureC": 20
},
"output": {
"langAnnualRainFactor": 50
}
}Limitations and assumptions
Its unit-dependent ratio should not be read as a calibrated drought probability. Apply the exact scope and assumptions explained above.
All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are explained above; extremely large inputs or outputs can also be rejected. Input errors differ from successful false results, empty match lists and unknown-evidence placeholders.
Alternative or Complementary methods
Use Thermohydrogram Ratio Classifier for a related task: A thermohydrogram compares precipitation with a scaled temperature-related reference.
Use Turc Irrigation Need Calculator for a related task: A Turc-style reference evapotranspiration estimate combines temperature, radiation and humidity.
References
-
Lang Rain Factor Calculator — tool.io
Similar or alternative tools
- Thermohydrogram Ratio Classifier
A thermohydrogram compares precipitation with a scaled temperature-related reference.
- Turc Irrigation Need Calculator
A Turc-style reference evapotranspiration estimate combines temperature, radiation and humidity.