Growing Degree Days (GDD)

Agriculture Math & Calculations Credits / request: 1

Calculates cumulative growing degree days from base and upper temperatures. Decision support, not agronomic advice.

POST https://api.apikodu.com/api/v1/agriculture/gdd

Documentation

Overview

Growing degree days. Weather from DB or dailyTemps. First lat/lon call creates a cell; if empty, code -256.

Authentication

Every request requires the x-api-key header. Credits used and remaining quota are returned in response headers (x-api-credits-used, x-api-remaining-credits, x-rate-limit-*).

Request

POST https://api.apikodu.com/api/v1/agriculture/gdd

JSON body. dailyTemps or latitude+longitude.

Parameters

Name	Type	Required	Default	Options	Description
`crop`	string	Optional	—	`wheat` `barley` `maize` `sunflower` `cotton` `potato` `tomato` `rapeseed` `oats` `rye` `sugarbeet` `grape` `apple` `chickpea` `lentil`	Crop code. baseTemp required if empty.
`fromDate`	string	* Required	—	—	YYYY-MM-DD
`toDate`	string	* Required	—	—	Max 366 days.
`baseTemp`	number	Optional	—	—	GDD base °C.
`upperTemp`	number	Optional	—	—	Upper cap °C.
`latitude`	number	Optional	—	—	0.1° cell. Required without dailyTemps.
`longitude`	number	Optional	—	—	Longitude.
`includeDaily`	boolean	Optional	`true`	`true` `false`	Daily breakdown.
`dailyTemps`	json	Optional	—	—	[{date,tmin,tmax}]. Overrides lat/lon.

Response

Name	Type	Description
`gddCumulative`	number	Accumulated GDD over the window. max(0, (tmin+tmax)/2 − baseTemp), capped by upperTemp.
`gddAveragePerDay`	number	gddCumulative / daysWithData. 0 when no data.
`baseTemp`	number	Base temperature °C used (request or crop table).
`upperTemp`	number	Upper cap °C. Null if unused.
`crop`	string	Normalized crop code (wheat, maize ...). Null if omitted.
`fromDate`	string	Window start YYYY-MM-DD.
`toDate`	string	Window end YYYY-MM-DD.
`daysTotal`	integer	Calendar days in the window (fromDate..toDate).
`daysWithData`	integer	Days that have temperature data.
`missingCount`	integer	Days without data. missingDates.Length.
`missingDates`	array	YYYY-MM-DD list of missing days.
`gridLatitude`	number	0.1° cell latitude. Null when dailyTemps was used.
`gridLongitude`	number	0.1° cell longitude. Null when dailyTemps was used.
`stages`	array	Crop phenology thresholds. Empty array without crop.
`stages[].code`	string	Threshold code. Example: emergence, flowering.
`stages[].threshold`	number	Cumulative GDD required for this stage.
`stages[].reached`	boolean	true when gddCumulative >= threshold.
`daily`	array	Daily rows when includeDaily=true. Empty array when false.
`daily[].date`	string	Day YYYY-MM-DD.
`daily[].tmin`	number	Daily minimum °C.
`daily[].tmax`	number	Daily maximum °C.
`daily[].gdd`	number	GDD for that day.
`daily[].gddCumulative`	number	Running cumulative GDD through that day.
`method`	string	Calculation method. gdd-average-capped for this API.
`source`	string	user: dailyTemps or et0Mm. db: tarim_hava cell.
`disclaimer`	string	Decision-support disclaimer. Not agronomic advice or a prescription.

Errors

HTTP	code	Description
`400`	`-249`	Body missing; both crop and baseTemp missing; dailyTemps > 366, or tmin/tmax missing/invalid.
`400`	`-254`	fromDate/toDate missing, not YYYY-MM-DD, or the window exceeds 366 days.
`400`	`-255`	latitude/longitude are required without dailyTemps. Latitude -90..90, longitude -180..180.
`429`	`-316`	Daily new location (cell) limit (50) reached. Previously requested locations keep working; new locations next day (UTC). Retry-After header gives seconds until end of day.
`503`	`-256`	Cell created; Worker is filling the last 730 days. Retry in a few minutes.
`400`	`-251`	No weather for this location/date (and no dailyTemps).
`401`	`-100`	x-api-key is missing, empty, malformed, inactive, banned, expired, IP-restricted, or not allowed for this API.
`429`	`-221`	Per-minute request limit exceeded. Response headers: x-rate-limit-limit, x-rate-limit-remaining, x-rate-limit-reset.
`429`	—	Package credit quota cannot cover this request. Body may be { error, limit, currentUsage, requestCost } (no code field).
`500`	`-1`	Unexpected server error. message is a generic error text without technical details.

Notes

Success body is { data: { ... } }. Error body is { code, message }. code is an ApiResponseCode enum value (negative integer).

Sample response

{
  "data": {
    "gddCumulative": 18.5,
    "gddAveragePerDay": 9.25,
    "baseTemp": 4.0,
    "upperTemp": 30.0,
    "crop": "wheat",
    "fromDate": "2026-03-01",
    "toDate": "2026-03-02",
    "daysTotal": 2,
    "daysWithData": 2,
    "missingCount": 0,
    "missingDates": [],
    "stages": [
      {
        "code": "emergence",
        "threshold": 120.0,
        "reached": false
      }
    ],
    "method": "gdd-average-capped",
    "source": "user",
    "disclaimer": "Decision support only. Not agronomic advice."
  }
}

Code samples

  
      const response = await fetch('https://api.apikodu.com/api/v1/agriculture/gdd', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'x-api-key': 'YOUR_API_KEY'
        },
        body: JSON.stringify({
          name: 'example',
          value: 123
        })
      });

      const data = await response.json();
      console.log(data);

  
      import requests

      headers = {
          'Content-Type': 'application/json',
          'x-api-key': 'YOUR_API_KEY'
      }

      payload = {
          'name': 'example',
          'value': 123
      }

      response = requests.post('https://api.apikodu.com/api/v1/agriculture/gdd', headers=headers, json=payload)
      data = response.json()
      print(data)

  
      using var client = new HttpClient();
      client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");

      var payload = new { name = "example", value = 123 };
      var json = JsonSerializer.Serialize(payload);
      var content = new StringContent(json, Encoding.UTF8, "application/json");

      var response = await client.PostAsync("https://api.apikodu.com/api/v1/agriculture/gdd", content);
      response.EnsureSuccessStatusCode();

      var data = await response.Content.ReadAsStringAsync();
      Console.WriteLine(data);

 
     $data = [
         'name' => 'example',
         'value' => 123
     ];

     $response = file_get_contents('https://api.apikodu.com/api/v1/agriculture/gdd', false, stream_context_create([
         'http' => [
             'header' => "x-api-key: YOUR_API_KEY"
         ],
         'method'  => 'POST',"
         'content' => json_encode($data)
      ]));

      print_r(json_decode($response, true));

  
      curl -X POST 'https://api.apikodu.com/api/v1/agriculture/gdd' \
        -H 'Content-Type: application/json' \
        -H 'x-api-key: YOUR_API_KEY' \
        -d '{
          "name": "example",
          "value": 123
        }'

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