Winkler Index GDD Region Classifier

Resolve an already supplied seasonal GDD into caller Winkler-region policy bands, using lower-inclusive boundaries; no duplicate GDD accumulation, mutable region constants or crop recommendation.

Description

Winkler regions group vineyard climates by accumulated growing degree days.

Winkler regions group vineyard climates by accumulated growing degree days. This tool classifies an already calculated seasonal heat total using boundaries you supply, so the threshold system and the season must be chosen before classification.^[1]

Resolve an already supplied seasonal GDD into caller Winkler-region policy bands, using lower-inclusive boundaries; no duplicate GDD accumulation, mutable region constants or crop recommendation.

When to use Winkler Index GDD Region Classifier

Use this tool to resolve an already supplied seasonal GDD into caller Winkler-region policy bands, using lower-inclusive boundaries; no duplicate GDD accumulation, mutable region constants or crop recommendation.

Prepare the climate observations and any independently chosen thresholds or model parameters. Confirm units, daily coverage, time order and the intended seasonal window.

How to use Winkler Index GDD Region Classifier and understand its results

Prepare the climate observations and any independently chosen thresholds or model parameters. Confirm units, daily coverage, time order and the intended seasonal window.
Enter seasonGddCelsiusDays, callerRegionLowerEdgesCelsiusDays using the field table and calculation rules, then run the tool.
Read callerWinklerRegionIndex, withinRegionOffsetCelsiusDays. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
seasonGddCelsiusDays	Season gdd celsius days	number	Required
callerRegionLowerEdgesCelsiusDays	Caller region lower edges celsius days	list of number	Required

Enter a nonnegative growing degree-day total and at least two nonnegative, strictly increasing lower edges, beginning at zero. The selected region is the last edge less than or equal to the total. Equality belongs to the region starting at that edge. Results include a zero-based region index and the heat total above its lower edge.

Each sequence checked for increasing order must contain at least two strictly increasing values.

region index = largest i for which GDD ≥ lowerEdge_i; offset = GDD − lowerEdge_region

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
callerWinklerRegionIndex	Caller winkler region index	number
withinRegionOffsetCelsiusDays	Within region offset celsius days	number

json

{
  "input": {
    "seasonGddCelsiusDays": 1500,
    "callerRegionLowerEdgesCelsiusDays": [
      0,
      1000,
      2000
    ]
  },
  "output": {
    "callerWinklerRegionIndex": 1,
    "withinRegionOffsetCelsiusDays": 500
  }
}

Limitations and assumptions

No published region boundaries or growing season are built in, and the tool does not accumulate daily temperatures. Confirm the degree-day unit, base temperature and seasonal window match your boundary system. A region index alone does not establish suitability for a grape variety.

Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Growing Degree Days Single Sinusoid Method: Integrate ideal single-sinusoid daily temperature excess between caller lower and horizontal upper cutoffs analytically; differs from arithmetic daily-mean GDD and is not a development-event forecast. For a complementary task, use Huglin Heliothermal Index: Calculate Huglin mean/maximum heliothermal contributions over caller supplied season with caller latitude/daylength coefficient and base; no implicit hemisphere calendar or grape suitability classification.

References

Winkler Index GDD Region Classifier — tool.io

Similar or alternative tools

Growing Degree Days Single Sinusoid Method
Integrate ideal single-sinusoid daily temperature excess between caller lower and horizontal upper cutoffs analytically; differs from arithmetic daily-mean GDD and is not a development-event forecast.
Huglin Heliothermal Index
Calculate Huglin mean/maximum heliothermal contributions over caller supplied season with caller latitude/daylength coefficient and base; no implicit hemisphere calendar or grape suitability classification.