docsadvancedlead-time

Lead Time Analysis

GET/api/v1/accuracy/by-lead-time

Shows how forecast accuracy degrades with lead time. Returns stats per lead time bucket (0-6h, 6-12h, 12-24h, 24-48h, 48-72h, 72h+). Omit station for network-wide; use station_id or city to filter to one station.

Parameters

Name	Type	Required	Description
`days`	integer	optional	Rolling window Default: 90
`date_from`	YYYY-MM-DD	optional	Window start
`date_to`	YYYY-MM-DD	optional	Window end
`station_id`	string	optional	Filter to one station (e.g. KLAX)
`city`	string	optional	Filter by city name (resolves to station)
`metric`	string	optional	high (default) or low — daily high vs daily low verification Default: high

Response Fields

Field	Type	Description
`lead_time_bucket`	string	Time range label (e.g., 0-6h)
`description`	string	Human-readable bucket description
`stats`	object	{ verification_pairs, unique_days, mean_error, std_dev, mae, rmse }

← Accuracy By Station

Weather Regime →

cURL

# All stations (default)
curl -s -H "Authorization: Bearer $API_KEY" "https://api.deltadaemon.com/api/v1/accuracy/by-lead-time?days=90"

# One station
curl -s -H "Authorization: Bearer $API_KEY" "https://api.deltadaemon.com/api/v1/accuracy/by-lead-time?days=90&station_id=KLAX"

JSON

{
  "success": true,
  "data": [
    {
      "lead_time_bucket": "0-6h",
      "label": "0–6 Hours Before Target Date",
      "description": "Forecasts issued 0-6 hours before the start of the target date (local midnight). Same-day morning updates.",
      "stats": {
        "verification_pairs": 67,
        "unique_days": 3,
        "mean_error": 1.64,
        "std_dev": 3.41,
        "mae": 2.77,
        "rmse": 3.76,
        "abs_error_p50": 1.8,
        "abs_error_p90": 6.3,
        "abs_error_p95": 7.88
      }
    }
  ],
  "metadata": {
    "generated_at": "2026-02-22T07:55:03.435578927Z",
    "days_analyzed": 30,
    "period_start": "2026-01-23",
    "period_end": "2026-02-22",
    "total_records": 872,
    "query_time_ms": 11
  }
}

cURL

# All stations (default)
curl -s -H "Authorization: Bearer $API_KEY" "https://api.deltadaemon.com/api/v1/accuracy/by-lead-time?days=90"

# One station
curl -s -H "Authorization: Bearer $API_KEY" "https://api.deltadaemon.com/api/v1/accuracy/by-lead-time?days=90&station_id=KLAX"

JSON

{
  "success": true,
  "data": [
    {
      "lead_time_bucket": "0-6h",
      "label": "0–6 Hours Before Target Date",
      "description": "Forecasts issued 0-6 hours before the start of the target date (local midnight). Same-day morning updates.",
      "stats": {
        "verification_pairs": 67,
        "unique_days": 3,
        "mean_error": 1.64,
        "std_dev": 3.41,
        "mae": 2.77,
        "rmse": 3.76,
        "abs_error_p50": 1.8,
        "abs_error_p90": 6.3,
        "abs_error_p95": 7.88
      }
    }
  ],
  "metadata": {
    "generated_at": "2026-02-22T07:55:03.435578927Z",
    "days_analyzed": 30,
    "period_start": "2026-01-23",
    "period_end": "2026-02-22",
    "total_records": 872,
    "query_time_ms": 11
  }
}