{
  "site": "glacier",
  "siteName": "Glacier National Park",
  "region": "St. Mary, MT",
  "date": "2026-09-20",
  "score": 87,
  "verdict": "Excellent",
  "headline": "Excellent night. Moon down after 1:30am, clear skies.",
  "headlineLead": "Excellent night",
  "headlineDetail": "moon down after 1:30am, clear skies",
  "milkyWay": {
    "visible": false,
    "maxAltitudeDeg": 7.3,
    "hoursUseful": 0,
    "bestAt": "9:25pm",
    "note": "Milky Way core only reaches 7.3°, low enough that haze takes most of it"
  },
  "window": {
    "darkFrom": "9:25pm",
    "darkTo": "5:33am",
    "hours": 8.12,
    "bestFrom": "1:30am",
    "bestTo": "5:33am"
  },
  "factors": [
    {
      "key": "cloud",
      "name": "Cloud",
      "score": 100,
      "weight": 38,
      "note": "0% cloud, essentially clear"
    },
    {
      "key": "moon",
      "name": "Moon",
      "score": 85,
      "weight": 31,
      "note": "waxing gibbous at 73%, sets 1:30am, dark after that"
    },
    {
      "key": "darkness",
      "name": "Darkness",
      "score": 90,
      "weight": 19,
      "note": "8h07m of astronomical darkness, 9:25pm–5:33am"
    },
    {
      "key": "transparency",
      "name": "Transparency",
      "score": 48,
      "weight": 12,
      "note": "Dewpoint spread 6.8°C, some haze possible"
    }
  ],
  "weatherBacked": true,
  "confidence": "full",
  "dataSources": {
    "astronomy": "SunCalc (local computation)",
    "weather": "Open-Meteo"
  }
}