How to Read a METAR: Airport Weather Codes Decoded

A METAR looks like a run of letters and numbers that someone typed with the spacebar stuck. It is not random. A METAR is a routine surface weather observation, taken at an airport on a fixed schedule and coded into a format that any pilot, dispatcher or airport operations desk anywhere in the world can read the same way, without translation. The format is set by the International Civil Aviation Organization and the World Meteorological Organization, and in the United States it is described in the FAA's Aeronautical Information Manual (FAA AIM, Chapter 7, Section 1, captured 2026-09-23). Once you know the order the fields come in, the string stops looking like noise and starts reading like a short, dense paragraph: where, when, wind, how far you can see, what is falling from the sky, what the clouds are doing, how warm it is, and what the barometer reads.

This guide walks the fields in the order they appear, using the Dubai, Singapore and Doha airport pages as anchors, because a code means more once you can picture the airport it describes. Every example string below is a sample built to show the format, not an actual reading for any airport on any particular day.

What a METAR actually is

METAR stands for Meteorological Aerodrome Report, and it is issued roughly once an hour (more often around a fast-changing weather event) by an automated or human-staffed weather station at the airport. The NWS Aviation Weather Center's own decoding reference describes it as the standard format for hourly surface weather observations used across international aviation (aviationweather.gov, captured 2026-09-23). It is not a forecast. A forecast for the same airport, covering the hours ahead rather than the moment the report was taken, is a separate product called a TAF (Terminal Aerodrome Forecast), built from the same coded vocabulary but describing what is expected rather than what a sensor or observer just measured.

Pilots use a METAR to decide whether conditions support the approach they are planning. Airport operations use it to decide whether to de-ice, close a runway for standing water, or call a ground stop. Air traffic control uses it to set the active runway. None of those readers is guessing at the string; they are reading a fixed sequence of fields, each with its own coded shape.

Station, time and wind

The report opens with a four-letter ICAO station code (Dubai's is OMDB, Singapore Changi's is WSSS, Doha Hamad's is OTHH), followed by a six-digit day-and-time group ending in Z for Coordinated Universal Time, for example 251450Z for the 25th of the month at 1450 UTC. Every METAR is timed in UTC regardless of the airport's local zone, which is why a METAR from a Gulf or Southeast Asian airport reads several hours "behind" the wall clock on the ground.

Wind comes next as a three-digit direction (in degrees, rounded to the nearest ten, measured from true north) and a two- or three-digit speed in knots, for example 27012KT for wind from 270 degrees at 12 knots. A trailing group like 18025G35KT adds a gust value: wind from 180 degrees, sustained at 25 knots, gusting to 35. VRB in place of a direction means the wind is too variable to report as a single heading, usually in light and shifting conditions.

Visibility and present weather

Visibility follows as a distance, in statute miles in the US format and in metres almost everywhere else, representing how far a ground observer or automated sensor can see in the prevailing direction. 9999 in the metric format means ten kilometres or more, effectively unlimited for flight-planning purposes.

Present weather, when there is any to report, is coded as short two- or three-letter groups built from an intensity prefix, a descriptor and a phenomenon: -RA is light rain, +TSRA is a thunderstorm with heavy rain, BR is mist, FG is fog. These codes are additive and can stack (-SHRA for light rain showers), and their absence from a report is itself informative: no weather group means nothing significant enough to code was observed at the time.

Sky condition: reading the cloud layers

Cloud layers are reported from lowest to highest, each as a three-letter coverage code plus a three-digit height in hundreds of feet above ground level. FEW, SCT, BKN and OVC stand for few, scattered, broken and overcast, in increasing order of how much of the sky each layer covers. A report reading SCT025 BKN045 OVC080 describes a scattered layer at 2,500 feet, a broken layer at 4,500 feet and an overcast layer at 8,000 feet, stacked in that order. SKC or CLR means no clouds detected at or below the station's reporting limit; CAVOK, used outside the US, is shorthand for "ceiling and visibility okay," standing in for the entire visibility and cloud portion of the report when conditions clear a set threshold.

Temperature, dew point and altimeter

A slash-separated pair of two-digit numbers gives air temperature and dew point in degrees Celsius, for example 24/18 for 24 degrees with an 18-degree dew point. A leading M marks a negative value (M02/M05 is minus 2 over minus 5). The gap between the two numbers is a rough proxy for how close the air is to saturation: a small gap points toward fog or low cloud risk, a wide one toward drier air.

The report closes its main body with an altimeter setting, given as A followed by four digits in the US format (inches of mercury times 100, so A3005 is 30.05 inches) or Q followed by four digits everywhere else (hectopascals, so Q1013 is standard sea-level pressure). Pilots set this value into their altimeter so the instrument reads altitude above sea level based on current local pressure, rather than altitude relative to whatever pressure happened to be set before landing.

The remarks group

Anything after RMK is the remarks section, an open-ended set of supplementary codes: peak wind since the last report, precise sea-level pressure, hourly precipitation, or a note that the station is an automated one with no human observer to confirm what the sensors are reporting (AO1 or AO2). Remarks are the part of a METAR most likely to vary between countries and even between stations, so a decoder built for the US format will not always resolve a remark from a station using a different national convention.

How TrackMyWings helps

TrackMyWings™ is a live flight-tracking platform in development, India-first in go-to-market with worldwide coverage. Knowing how to read the weather code for an airport is one half of the picture; knowing what that weather is doing to a specific flight is the other, and that is the half TrackMyWings is built around. A private beta shipped on 2026-08-24: Android only, on the Play internal testing track for a small group of named testers. Trip management, gate and status alerts and a shared view for the people waiting on a flight are planned for launch rather than available today, and public launch has no fixed date. Our flight tracking blog covers more of the codes and terms that show up around a delay while that build continues.

Questions people ask

What does METAR stand for? Meteorological Aerodrome Report, the standard hourly surface weather observation format used at airports worldwide.

Is a METAR a forecast? No. A METAR is a report of conditions already observed. The forecast built from the same coded vocabulary is a separate product called a TAF, Terminal Aerodrome Forecast.

What does CAVOK mean? "Ceiling and visibility okay," used outside the US in place of the visibility and cloud fields when conditions clear a defined threshold for both.

Why is the time in a METAR always in Z? Z marks Coordinated Universal Time. Every METAR worldwide is timed in UTC so a reader anywhere can compare reports across airports without converting local zones first.

Does every country format a METAR the same way? The core fields follow the same ICAO/WMO structure everywhere, but units differ (miles versus metres for visibility, inches of mercury versus hectopascals for pressure), and the remarks section varies most between national weather services.

Sources

• FAA Aeronautical Information Manual, Chapter 7, Section 1 (Meteorological Services): https://www.faa.gov/air_traffic/publications/atpubs/aim_html/chap7_section_1.html, captured 2026-09-23
• NWS Aviation Weather Center, METAR decoding reference: https://www.aviationweather.gov/metar/help, captured 2026-09-23