A METAR is a routine aviation weather observation issued by an airport, usually every hour. It packs current wind, visibility, weather, cloud, temperature, and pressure into a compact coded string that this tool translates into readable sentences.

What time zone is the report in?

The day-and-time group ends in Z, meaning it is in UTC, also called Zulu time. The first two digits are the day of the month and the next four are the hour and minute, so 121956Z is the 12th at 19:56 UTC.

What does CAVOK mean?

CAVOK stands for ceiling and visibility OK. It means visibility is 10 kilometres or more, there is no cloud below 5,000 feet or below the highest minimum sector altitude, no cumulonimbus, and no significant weather. The decoder expands it for you.

How are wind gusts shown?

A wind group like 28012G18KT means the wind is from 280 degrees at 12 knots gusting to 18 knots. The decoder breaks out the direction, steady speed, and gust separately so the values are unambiguous.

Why are some groups not decoded?

Anything after the RMK keyword is a remarks section that often contains automated or country-specific coding, which the decoder shows raw. A genuinely unrecognised group before remarks is flagged so you can verify it against an official source.

What is the METAR Decoder?

Paste a raw METAR and get a field-by-field plain-English translation of station, time, wind, visibility, weather, sky, temperature, dewpoint, and altimeter. Student pilots and non-aviators use it to read aeronautical weather reports. Runs in your browser. It runs free in your browser on Gera Tools, with nothing uploaded.

METAR Decoder — Gera Tools

Name: METAR Decoder
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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A METAR squeezes a full airport weather observation into a dense line of codes that is hard to read until you learn the format. This decoder parses a pasted METAR group by group and explains each field in plain English.

How it works

The decoder splits the report into its standard groups and translates each one against the international METAR format:

KSFO 121956Z 28012G18KT 10SM FEW015 SCT200 18/12 A3001
 └station └time(UTC)  └wind   └vis  └cloud  └cloud └temp └altimeter

Wind groups are read as direction, speed, and optional gust; visibility handles statute miles, metres, and CAVOK; cloud layers give coverage and base in feet; and the altimeter is converted between inches of mercury and hectopascals.

Field-by-field guide

Station identifier — the four-letter ICAO code. KSFO is San Francisco; EGLL is London Heathrow. The leading K means a US station; E means Europe.

Time group — 121956Z means the 12th day of the month at 19:56 UTC. METAR times are always Zulu (UTC).

Wind — 28012G18KT is wind from 280 degrees (roughly west) at 12 knots, gusting to 18 knots. VRB instead of a direction means variable below 3 knots. When the speed is 00 the wind is calm.

Visibility — 10SM is 10 statute miles (US). European METARs use metres: 9999 means 10 km or more. CAVOK replaces the visibility, weather, and cloud groups when all three meet the all-clear criteria.

Present weather — two- or three-letter codes for precipitation and other phenomena. Common ones:

Code	Meaning
RA	Rain
SN	Snow
FG	Fog
TS	Thunderstorm
-RA	Light rain
+SN	Heavy snow
RASN	Rain and snow

A - prefix means light; no prefix is moderate; + is heavy.

Sky condition — layers are listed from lowest to highest in hundreds of feet. Coverage codes: FEW (1–2 oktas), SCT scattered (3–4), BKN broken (5–7), OVC overcast (8). SKC or CLR means clear.

Temperature / dewpoint — 18/12 means 18°C air temperature and 12°C dewpoint. A M prefix means below zero: M02/M05 is −2°C with −5°C dewpoint. A narrow temperature–dewpoint spread signals high humidity and fog risk.

Altimeter — A3001 is 30.01 inHg (US format). European reports use Q and hectopascals: Q1013 is standard pressure.

Example decoded

The sample report KSFO 121956Z 28012G18KT 10SM FEW015 SCT200 18/12 A3001 translates as: San Francisco International, observed on the 12th at 19:56 UTC, wind from 280 degrees at 12 knots gusting to 18 knots, visibility 10 statute miles, a few clouds at 1,500 ft and scattered at 20,000 ft, temperature 18°C dewpoint 12°C, altimeter 30.01 inches of mercury. Everything after RMK is shown raw because remarks often use automated or country-specific coding. Always confirm weather against an official briefing source before any flight.