AviationWeather METAR Observation is a JSON Structure definition published by Aviation Weather Center, describing 32 properties, of which 3 are required. It conforms to the https://json-structure.org/meta/core/v0/# meta-schema.
{
"$schema": "https://json-structure.org/meta/core/v0/#",
"$id": "https://raw.githubusercontent.com/api-evangelist/aviationweather/refs/heads/main/json-structure/aviationweather-metar-structure.json",
"name": "AviationWeather METAR Observation",
"description": "Decoded METAR (or SPECI/SYNOP/BUOY/CMAN) aviation weather observation as returned by GET /api/data/metar?format=json.",
"type": "object",
"required": [
"icaoId",
"obsTime",
"rawOb"
],
"properties": {
"icaoId": {
"type": "string",
"description": "ICAO identifier of the reporting station.",
"examples": [
"KORD"
]
},
"receiptTime": {
"type": "string",
"description": "Time the observation was received (yyyy-mm-dd hh:mm:ss.sssZ)."
},
"obsTime": {
"type": "int32",
"description": "Observation time (UNIX epoch seconds)."
},
"reportTime": {
"type": "string",
"description": "Time of the report (yyyy-mm-dd hh:mm:ss.sssZ)."
},
"temp": {
"type": [
"number",
"null"
],
"description": "Temperature in degrees Celsius."
},
"dewp": {
"type": [
"number",
"null"
],
"description": "Dewpoint temperature in degrees Celsius."
},
"wdir": {
"type": [
"integer",
"string",
"null"
],
"description": "Wind direction in degrees, or VRB for variable."
},
"wspd": {
"type": [
"integer",
"null"
],
"description": "Wind speed in knots."
},
"wgst": {
"type": [
"integer",
"null"
],
"description": "Wind gust in knots."
},
"visib": {
"type": [
"number",
"string",
"null"
],
"description": "Visibility in statute miles; \"10+\" denotes >10 SM."
},
"altim": {
"type": [
"number",
"null"
],
"description": "Altimeter setting in hectopascals."
},
"slp": {
"type": [
"number",
"null"
],
"description": "Sea level pressure in hectopascals."
},
"wxString": {
"type": [
"string",
"null"
],
"description": "Encoded present weather string (e.g. -RA, +TSRA)."
},
"presTend": {
"type": [
"number",
"null"
],
"description": "Pressure tendency over last 3 hours in hPa."
},
"maxT": {
"type": [
"number",
"null"
],
"description": "Maximum temperature over last 6 hours (C)."
},
"minT": {
"type": [
"number",
"null"
],
"description": "Minimum temperature over last 6 hours (C)."
},
"maxT24": {
"type": [
"number",
"null"
],
"description": "Maximum temperature over last 24 hours (C)."
},
"minT24": {
"type": [
"number",
"null"
],
"description": "Minimum temperature over last 24 hours (C)."
},
"precip": {
"type": [
"number",
"null"
],
"minimum": 0,
"description": "Precipitation over last hour (inches)."
},
"pcp3hr": {
"type": [
"number",
"null"
],
"minimum": 0,
"description": "Precipitation over last 3 hours (inches)."
},
"pcp6hr": {
"type": [
"number",
"null"
],
"minimum": 0,
"description": "Precipitation over last 6 hours (inches)."
},
"pcp24hr": {
"type": [
"number",
"null"
],
"minimum": 0,
"description": "Precipitation over last 24 hours (inches)."
},
"snow": {
"type": [
"number",
"null"
],
"minimum": 0,
"description": "Snow depth (inches)."
},
"vertVis": {
"type": [
"integer",
"null"
],
"minimum": 0,
"description": "Vertical visibility in feet."
},
"metarType": {
"type": "string",
"enum": [
"METAR",
"SPECI",
"SYNOP",
"BUOY",
"CMAN"
],
"description": "Observation encoding type."
},
"rawOb": {
"type": "string",
"description": "Raw text of the observation."
},
"lat": {
"type": "double",
"description": "Latitude of site (decimal degrees)."
},
"lon": {
"type": "double",
"description": "Longitude of site (decimal degrees)."
},
"elev": {
"type": "int32",
"description": "Elevation in meters."
},
"name": {
"type": "string",
"description": "Full name of the site."
},
"clouds": {
"type": "array",
"description": "Cloud layers reported.",
"items": {
"type": "object",
"properties": {
"cover": {
"type": "string",
"enum": [
"CLR",
"SKC",
"NSC",
"FEW",
"SCT",
"BKN",
"OVC",
"VV",
"NCD",
"TCU",
"CB"
],
"description": "Cloud cover code."
},
"base": {
"type": [
"integer",
"null"
],
"description": "Cloud base in feet AGL."
},
"type": {
"type": [
"string",
"null"
],
"description": "Cloud type qualifier."
}
}
}
},
"fltCat": {
"type": "string",
"enum": [
"VFR",
"MVFR",
"IFR",
"LIFR",
""
],
"description": "Flight category."
}
}
}