{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://point-observation.weather.mg/schemas/observation",
  "title": "DTN Weather Observation",
  "description": "Schema representing a weather observation or forecast data point from the DTN Weather API.",
  "type": "object",
  "required": ["location"],
  "properties": {
    "stationId": {
      "type": "string",
      "description": "Weather station identifier (ICAO, WMO, or DTN identifier)",
      "examples": ["KMSP", "KORD", "72658"]
    },
    "stationName": {
      "type": "string",
      "description": "Human-readable station name"
    },
    "observedAt": {
      "type": "string",
      "format": "date-time",
      "description": "ISO 8601 timestamp of observation"
    },
    "location": {
      "$ref": "#/$defs/GeoLocation"
    },
    "units": {
      "type": "string",
      "description": "Unit system for all measurements",
      "enum": ["SI", "US"]
    },
    "temperature": {
      "$ref": "#/$defs/TemperatureData"
    },
    "wind": {
      "$ref": "#/$defs/WindData"
    },
    "precipitation": {
      "$ref": "#/$defs/PrecipitationData"
    },
    "atmosphere": {
      "$ref": "#/$defs/AtmosphericData"
    },
    "visibility": {
      "type": "number",
      "description": "Horizontal visibility in meters (SI) or miles (US)",
      "minimum": 0
    },
    "weatherSymbol": {
      "type": "integer",
      "description": "WMO present weather code (0-99)",
      "minimum": 0,
      "maximum": 99
    },
    "cloudCoverInPercent": {
      "type": "number",
      "description": "Total cloud cover percentage",
      "minimum": 0,
      "maximum": 100
    },
    "uvIndex": {
      "type": "number",
      "description": "UV index (0-11+)",
      "minimum": 0
    },
    "soilTemperatureInCelsius": {
      "type": "number",
      "description": "Soil temperature at surface in degrees Celsius"
    },
    "evapotranspirationInMillimeter": {
      "type": "number",
      "description": "Potential evapotranspiration in mm (agricultural use)",
      "minimum": 0
    }
  },
  "$defs": {
    "GeoLocation": {
      "type": "object",
      "required": ["latitude", "longitude"],
      "properties": {
        "latitude": {
          "type": "number",
          "format": "double",
          "minimum": -90,
          "maximum": 90
        },
        "longitude": {
          "type": "number",
          "format": "double",
          "minimum": -180,
          "maximum": 180
        },
        "elevationInMeter": {
          "type": "number",
          "description": "Elevation above mean sea level in meters"
        }
      }
    },
    "TemperatureData": {
      "type": "object",
      "properties": {
        "airTemperatureInCelsius": {
          "type": "number",
          "description": "Air temperature at 2m height in degrees Celsius"
        },
        "feelsLikeTemperatureInCelsius": {
          "type": "number",
          "description": "Apparent temperature (heat index or wind chill)"
        },
        "dewPointInCelsius": {
          "type": "number",
          "description": "Dew point temperature in degrees Celsius"
        },
        "maxTemperatureInCelsius": {
          "type": "number",
          "description": "Maximum temperature over the period"
        },
        "minTemperatureInCelsius": {
          "type": "number",
          "description": "Minimum temperature over the period"
        },
        "wetBulbTemperatureInCelsius": {
          "type": "number",
          "description": "Wet-bulb temperature in degrees Celsius"
        }
      }
    },
    "WindData": {
      "type": "object",
      "properties": {
        "windSpeedInMeterPerSecond": {
          "type": "number",
          "description": "10-minute average wind speed at 10m height",
          "minimum": 0
        },
        "windDirectionInDegree": {
          "type": "number",
          "description": "Wind direction in meteorological degrees (0=N, 90=E, 180=S, 270=W)",
          "minimum": 0,
          "maximum": 360
        },
        "windGustInMeterPerSecond": {
          "type": "number",
          "description": "Maximum wind gust speed over the period",
          "minimum": 0
        }
      }
    },
    "PrecipitationData": {
      "type": "object",
      "properties": {
        "precipitationAmountInMillimeter": {
          "type": "number",
          "description": "Total precipitation amount in millimeters",
          "minimum": 0
        },
        "precipitationProbabilityInPercent": {
          "type": "number",
          "description": "Probability of precipitation (0-100%)",
          "minimum": 0,
          "maximum": 100
        },
        "precipitationTypeCode": {
          "type": "integer",
          "description": "0=none, 1=rain, 2=snow, 3=sleet, 4=freezing rain, 5=mixed",
          "enum": [0, 1, 2, 3, 4, 5]
        },
        "snowfallAmountInCentimeter": {
          "type": "number",
          "description": "New snowfall amount in centimeters",
          "minimum": 0
        },
        "snowDepthInCentimeter": {
          "type": "number",
          "description": "Current snow depth on ground in centimeters",
          "minimum": 0
        }
      }
    },
    "AtmosphericData": {
      "type": "object",
      "properties": {
        "pressureInHectopascal": {
          "type": "number",
          "description": "Mean sea level pressure in hPa",
          "minimum": 800,
          "maximum": 1100
        },
        "pressureTendencyInHectopascal": {
          "type": "number",
          "description": "3-hour pressure tendency in hPa"
        },
        "relativeHumidityInPercent": {
          "type": "number",
          "description": "Relative humidity percentage",
          "minimum": 0,
          "maximum": 100
        }
      }
    }
  }
}