A METAR (Meteorological Terminal Air Report) is an international standard used to inform about the meteorological conditions in an airport, was introduced in the year 1968. These reports are updated periodically, commonly every half an hour or 1 hour, to adapt to new conditions. It is used widely by pilots to forecast the weather for the destination airport to know the meteorology and act accordingly to it.
The report is given for every ICAO airport and gives information about the wind, visibility, cloud covers, temperature, etc. The main structure of the METAR is like the following:
METAR – Location – Date – Wind – Visibility – Phenomenoms – Clouds – Temperature – Pressure
Let’s see an example of a METAR:
METAR LEBL 250730Z 33014KT 9999 FEW020 BKN038 22/13 Q1015 NOSIG
Although the general format of the METAR reports is a global standard, the specific fields vary somewhat between the international usage standard and that used within North America.
It is a 4 letter indicator according to ICAO
In our example: LEBL is the Barcelona Airport.
Date and Time
Day of the month, hour and minutes in UTC (Coordinated Universal Time) followed by the letter Z (Zulu)
250730Z (day 25 and 07:30 hour Zulu)
It is composed of two components:
- Direction rounded to the nearest ten degrees (Take into consideration for the address 360º available, knowing that 0º or 360º is the north, 90º is the east, 180º is the south and 270º the west)
- Average speed followed by KT (knots)
33014KT: 330 ° WITH 14 KNOTS
Prevailing visibility, in meters:
In our example we have:
9999: that’s 10000 meters of visibility.
Then comes the report of the clouds or precipitation:
|SKC||Sky clear (0/8)||FEW||Few (1-2/8)|
|SCT||Scattered (3-4/8)||BKN||Broken (5-7/8)|
|TCU||Towering Cumulus||NSC||No significant Clouds (Rarely used)|
Visibility, precipitation and others:
|PO||Swirl of dust or sand||DZ||Drizzle|
I have a little page that helps you decode the METAR codes or TAF codes. You only need to write the ICAO code of the airport or the METAR code to decode, then it shows you a table with all the code decoded.
In the next days, I will publish an API so you can decode and get the METARs automatically.