METAR / SPECI (ICAO)

Required roles: AIS PIB API — Roles
Base endpoint: https://ais-pib-api.ibosoft.net.tr:2087/opmet-decoder-metar-speci-icao
Reference documents: ICAO Doc 10157 PANS-MET, Ed. 1 (27/11/25) · ICAO Doc 8400 PANS-ABC, Ed. 9, Amend. 33 (8/11/18) · ICAO Annex 3, Ed. 20, Amend. 79 (5/11/20)
Attribution: show ibonav.aero or "Decoded by Ibosoft" wherever decoded output is displayed
Data sources: none — decodes the message supplied in the request.
Last updated: 17 OCT 2026

About the reference documents: Related Documents and Resources

Decodes a METAR or SPECI report into readable fields, following the PANS-MET template strictly. Optionally returns machine-readable values (parsed) and the position of every decoded token in the message (positions).

To get reports to decode, see METAR / SPECI. For U.S. format reports use METAR / SPECI (FAA); MET Format Check tells which decoder fits an aerodrome.

Endpoints

POST /opmet-decoder-metar-speci-icao/decode?pre_2021=false&parsed=false
Content-Type: application/json

{ "raw": "<METAR or SPECI text>" }

Parameters

Parameter	In	Default	Description
`raw`	body	—	Report text, at least 10 characters. Line breaks, extra spaces, lower case and a final `=` are accepted.
`pre_2021`	query	`false`	`true`: decode with the provisions in force until 3 November 2021 — Annex 3, Ed. 20, Amend. 79 (adds the State of the runway group, removed by Amend. 80)
`parsed`	query	`false`	`true`: add the `parsed` object with machine-readable values

How the template is processed

The decoder reads the message against PANS-MET Table A2-2, element by element, in template order:

Field names and wording come from the template and the related PANS-MET paragraphs: each output key is the element name of the template; values use the template's terms and units; trend box headers use the meanings of Table A2-3 and the definitions of 4.2.3. Abbreviations are expanded as defined in PANS-MET and PANS-ABC (Doc 8400).
M (mandatory) elements are always in the output. If an element is missing, or its value does not fit the template, it is null ([] for lists).
C (conditional) and O (optional) elements are in the output only when present in the message.
Lists: elements that can repeat are arrays, one entry per group — Runway visual range (one per runway, up to four), Present weather, Recent weather, Cloud (one per layer).
Trend forecast (O): each change group (NOSIG, BECMG, TEMPO) becomes one box in forecast_groups, with a header (label) and only the elements it contains. Trend groups never mix into the observed values or into parsed.
Strict template: a value that does not follow the template is not guessed. It is listed under Undecodable elements; neighbouring undecodable groups form one entry (e.g. RMK RWY36 240/16). Remarks (RMK …) are not part of the template and always appear there.
Special cases: NIL ends the report (M elements null); with CAVOK, visibility reads CAVOK (…) and cloud is []; wind 00000 is Calm; visibility 9999 is 10 km or more.

For the full list of elements and their templates, see PANS-MET Table A2-2.

Response

Example — PANS-MET Example A2-1:

METAR YUDO 221630Z 24004MPS 0600 R12/1000U DZ FG SCT010 OVC020 17/16 Q1018 BECMG TL1700 0800 FG BECMG AT1800 9999 NSW

{
  "Type of report": "METAR",
  "Location indicator": "YUDO",
  "Time of observation": "Day 22, 16:30 UTC",
  "Surface wind": "04 m/s from 240°T",
  "Visibility": "600 m",
  "Runway visual range": ["R12/1000 m upward tendency"],
  "Present weather": ["Drizzle", "Fog"],
  "Cloud": ["Scattered [3/8, 4/8] at 1000 ft AAL", "Overcast [8/8] at 2000 ft AAL"],
  "Air temperature": "17°C",
  "Dew-point temperature": "16°C",
  "Pressure values": "QNH 1018 hPa",
  "forecast_groups": [
    {
      "label": "Trend Forecast: Becoming - until 17:00 UTC - (The change is forecast to commence at the beginning of the trend forecast period and be completed by 17:00 UTC) (Note: …)",
      "label_start": 75, "label_end": 87,
      "Visibility": "800 m",
      "Weather": ["Fog"]
    },
    {
      "label": "Trend Forecast: Becoming - at 18:00 UTC - (The change is forecast to occur at 18:00 UTC (specified time)) (Note: …)",
      "label_start": 96, "label_end": 108,
      "Visibility": "10 km or more",
      "Weather": ["Nil significant weather"]
    }
  ],
  "marker_positions": [{"start": 75, "end": 87}, {"start": 96, "end": 108}],
  "positions": [{"start": 0, "end": 5}, "…"],
  "raw": "METAR YUDO 221630Z …"
}

Key	Description
element keys	Decoded elements, in template order
`forecast_groups`	Trend boxes (only when the report has a trend): `label`, `label_start`/`label_end` (header span in the message) and the box elements
`marker_positions`	Header spans of the trend boxes
`Undecodable elements`	Groups that do not follow the template (only when there are any)
`positions`	Character spans `{start, end}` in the normalized message (single spaces, upper case, no final `=`), one per decoded value in output order, then one per undecodable entry. Use them to highlight the source token of each value. When one token gives two values (e.g. `17/16` → air and dew-point temperature) the span is repeated.
`raw`	The message as received
`parsed`	Only with `parsed=true` (see below)

`parsed`

Machine-readable values of the observation (never of the trend):

Field	Type	Description
`utc_day`, `utc_time`	int, string	Day and time of observation (`"HHMM"`)
`wind_direction`	int, `"variable"`, null	Degrees true; `"variable"` for `VRB`; `null` for calm or missing
`wind_speed`, `wind_speed_unit`	int, string	Speed and `"KT"` / `"MPS"`
`wind_gust_speed`, `wind_gust_speed_unit`	int, string	Gust, if reported
`wind_variable_direction_1`, `wind_variable_direction_2`	int	Extremes of the directional variation (`nnnVnnn`)
`visibility`	string	Decoded visibility
`lowest_cloud_base`, `lowest_cloud_base_unit`	int, string	Lowest cloud base in `"FT"` (vertical visibility excluded)
`special_condition`	string	`"CAVOK"` or `null`
`qnh`, `qnh_unit`	float, string	QNH and `"hPa"`
`temperature`, `dewpoint` (+ `_unit`)	float, string	°C

All fields are null when the value is not in the report.

Errors

Code	Meaning
`400`	The message could not be parsed at all; `detail` explains why
`422`	`raw` is missing or shorter than 10 characters

An undecodable group is not an error: the response is 200 and the group is listed under Undecodable elements.

METAR / SPECI (ICAO)#

Endpoints#

Parameters#

How the template is processed#

Response#

parsed#

Errors#