docsadvancedweather-regime

Weather Regime

GET/api/v1/accuracy/by-weather-regime

Accuracy broken down by observed weather condition regime: clear, partly_cloudy, cloudy, precipitation, storm, fog, high_wind. Shows how NWS accuracy varies with weather conditions — forecasts tend to be less accurate during regime transitions.

Parameters

Name	Type	Required	Description
`station_id`	string	required	ICAO station identifier
`days`	integer	optional	Rolling window Default: 90
`metric`	string	optional	high (default) or low — daily high vs daily low verification Default: high

Response Fields

Field	Type	Description
`regime_type`	string	Weather condition category
`description`	string	Human-readable regime description
`frequency_pct`	float	How often this regime occurs (percentage)
`stats`	object	{ verification_pairs, unique_days, mean_error, std_dev, mae, rmse }

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cURL

curl -s -H "Authorization: Bearer $API_KEY" "https://api.deltadaemon.com/api/v1/accuracy/by-weather-regime?station_id=KLAX&days=90"

JSON

{
  "success": true,
  "data": [
    {
      "regime_type": "other",
      "description": "other",
      "frequency_pct": 51.06,
      "stats": {
        "verification_pairs": 24,
        "unique_days": 2,
        "mean_error": 2.46,
        "std_dev": 3.41,
        "mae": 3.31,
        "rmse": 4.15,
        "abs_error_p50": 3.3,
        "abs_error_p90": 6.5,
        "abs_error_p95": 6.8
      }
    },
    {
      "regime_type": "clear",
      "description": "Clear or mostly clear skies, sky cover below 25%",
      "frequency_pct": 21.28,
      "stats": {
        "verification_pairs": 10,
        "unique_days": 1,
        "mean_error": -0.6,
        "std_dev": 2.37,
        "mae": 1.8,
        "rmse": 2.32,
        "abs_error_p50": 1,
        "abs_error_p90": 4.1,
        "abs_error_p95": 4.55
      }
    }
  ],
  "metadata": {
    "generated_at": "2026-02-22T07:57:33.672547825Z",
    "local_generated_at": "2026-02-22T02:57:33-05:00",
    "days_analyzed": 30,
    "station_id": "KBOS",
    "station_timezone": "America/New_York"
  }
}

cURL

curl -s -H "Authorization: Bearer $API_KEY" "https://api.deltadaemon.com/api/v1/accuracy/by-weather-regime?station_id=KLAX&days=90"

JSON

{
  "success": true,
  "data": [
    {
      "regime_type": "other",
      "description": "other",
      "frequency_pct": 51.06,
      "stats": {
        "verification_pairs": 24,
        "unique_days": 2,
        "mean_error": 2.46,
        "std_dev": 3.41,
        "mae": 3.31,
        "rmse": 4.15,
        "abs_error_p50": 3.3,
        "abs_error_p90": 6.5,
        "abs_error_p95": 6.8
      }
    },
    {
      "regime_type": "clear",
      "description": "Clear or mostly clear skies, sky cover below 25%",
      "frequency_pct": 21.28,
      "stats": {
        "verification_pairs": 10,
        "unique_days": 1,
        "mean_error": -0.6,
        "std_dev": 2.37,
        "mae": 1.8,
        "rmse": 2.32,
        "abs_error_p50": 1,
        "abs_error_p90": 4.1,
        "abs_error_p95": 4.55
      }
    }
  ],
  "metadata": {
    "generated_at": "2026-02-22T07:57:33.672547825Z",
    "local_generated_at": "2026-02-22T02:57:33-05:00",
    "days_analyzed": 30,
    "station_id": "KBOS",
    "station_timezone": "America/New_York"
  }
}