Decode a METAR in plain language. Enter an airport ICAO code to fetch its latest observation, or paste a raw METAR to break it down group by group.
METAR (METeorological Aviation Report) reports weather information for an airport. The first part of the message is the ICAO code of the station.
Then the delivery time of the METAR is coded. The first two digits represent the day of the month, the last four represent the time.
METAR contain information regarding the wind, the visibility, the different cloud covers, the temperature, the dew point and the atmospheric pressure. It also contains data about the current weather and weather trends.
A routine METAR is issued every hour or every half hour, depending on the aerodrome. When conditions change significantly between two routine reports, a SPECI is issued instead so that crews are not left with stale information.
The report type tells you how the message was produced: METAR is a routine observation, SPECI a special observation triggered by a significant change, AUTO a fully automated observation with no human validation, and COR a corrected version of a report already sent.
The format of the METAR is the following:
AAAA: Station identifier: AAAA. It is the ICAO code of the station.
Wind information:
DDHHmmZ: Delivery time of the report: DDHHmmZ. DD represents the day of the month. HHmm represents the hours and the minutes. The final Z represents the ZULU time zone.
VVVV: represents the visibility in meters or VVVVSM when the visibility is in nautical miles (SM).
RAAa/VVVV: represents the runway visual range. It must starts with an R followed by the name of the runway and a / The digits after the / are the visual range.
ww: Multiple coded words representing the current weather.
NNNhhh: Multiple coded words representing the cloud layers
T'T'/T'dT'd: for the temperature and the dew point. If the temperature or the dew point are below 0 they are preceded by a M
QPPPP for the altimeter. If it starts by a Q the unit is hPA, if it starts by an A the unit is inHg
RMK: starts the remark part of the METAR and contains complementary information.
Here is the example report you can load from the form above, broken down group by group.
METAR EGLL 010820Z 27015KT 9999 FEW020 15/10 Q1013
A weather group combines an optional qualifier with one or more phenomena codes.
A cloud group gives an amount in oktas followed by the base height in hundreds of feet above aerodrome level.
A METAR is a coded report of the weather observed at an aerodrome at a given time. It covers wind, visibility, runway visual range, present weather, cloud, temperature, dew point and altimeter setting. It describes conditions as measured, not as forecast.
Read it group by group, in order: report type, ICAO station, day and time in UTC, wind, visibility, runway visual range, present weather, cloud layers, temperature and dew point, then altimeter setting. Anything after RMK is supplementary. Paste your report into the decoder above to see every group in plain language.
CAVOK stands for Ceiling And Visibility OK. It replaces the visibility, weather and cloud groups when visibility is 10 km or more, there is no cloud below 5 000 ft or below the highest minimum sector altitude, no cumulonimbus or towering cumulus at any height, and no significant weather.
QNH is the pressure setting that makes an altimeter read altitude above mean sea level. It appears in a METAR as Q followed by four digits in hectopascals, or A followed by four digits in hundredths of an inch of mercury. QFE, which makes the altimeter read height above the aerodrome, is not reported in a METAR.
Routine METARs are issued every hour or every half hour depending on the aerodrome. Between two routine reports, a SPECI is issued whenever conditions change significantly.
Both use the same format. A METAR is the scheduled routine observation; a SPECI is an unscheduled one, issued because something changed enough to matter — a drop in visibility or ceiling, the onset of a thunderstorm, or a significant wind shift.
A METAR describes the weather happening right now. If you need the forecast for the hours ahead, use the TAF decoder.