International METAR codes

The following is an example METAR from Burgas Airport in Burgas, Bulgaria. It was taken on 4 February 2005 at 16:00 Coordinated Universal Time (UTC).

METAR LBBG 041600Z 12012MPS 090V150 1400 R04/P1500N R22/P1500U +SN BKN022 OVC050 M04/M07 Q1020 NOSIG 8849//91=

• METAR indicates that the following is a standard hourly observation.
• LBBG is the ICAO airport code for Burgas Airport.
• 041600Z indicates the time of the observation. It is the day of the month (04) followed by the time of day (1600 Zulu time, which equals 4:00 pm Greenwich Mean Time or 6:00 pm local time).
• 12012MPS indicates the wind direction is from 120° (east-southeast) at a speed of 12 m/s (23 knots; 27 mph; 44 km/h). Speed measurements can be in knots (abbreviated KT) or meters per second (abbreviated MPS).
• 090V150 indicates the wind direction is varying from 90° true (east) to 150° true (south-southeast).
• 1400 indicates the prevailing visibility is 1,400 m (4,600 ft).
• R04/P1500N indicates the Runway Visual Range (RVR) along runway 04 is 1,500 m (4,900 ft) and not changing significantly.
• R22/P1500U indicates RVR along runway 22 is 1,500 m (4,900 ft) and rising.
• +SN indicates snow is falling at a heavy intensity. If any precipitation begins with a minus or plus (-/+), it's either light or heavy.
• BKN022 indicates a broken (over half the sky) cloud layer with its base at 2,200 ft (670 m) above ground level (AGL). The lowest "BKN" or "OVC" layer specifies the cloud ceiling.
• OVC050 indicates an unbroken cloud layer (overcast) with its base at 5,000 ft (1,500 m) above ground level (AGL).
• M04/M07 indicates the temperature is −4 °C (25 °F) and the dew point is −7 °C (19 °F). An M in front of the number indicates that the temperature/dew point is below zero Celsius.
• Q1020 indicates the current altimeter setting (in QNH) is 1,020 hPa (30.12 inHg).
• NOSIG is an example of a TREND forecast which is appended to METARs at stations while a forecaster is on watch. NOSIG means that no significant change is expected to the reported conditions within the next 2 hours.
• 8849//91 indicates the condition of the runway.
  • The first two characters indicate which runway is being described.
    • If there are two or more runways with the same number, some locations will use three characters (e.g. 25L and 25R). Otherwise, the left runway will use just its number and the right runway will add 50 (e.g. 25 = 25L and 75 = 25R).
    • 88 indicates all the airport's runways.
    • 99 indicates repetition of the last message as no new information received.
  • 4 means the runway is coated with dry snow
  • 9 means 51% to 100% of the runway is covered
  • // means the thickness of the coating was either not measurable or not affecting usage of the runway
  • 91 means the braking index is bad, in other words the tires have bad grip on the runway
• CAVOK is an abbreviation for Ceiling And Visibility OK, indicating no cloud below 5,000 ft (1,500 m) or the highest minimum sector altitude and no cumulonimbus or towering cumulus at any level, a visibility of 10 km (6 mi) or more and no significant weather change.^[9]
• = indicates the end of the METAR

North American METAR codes

North American METARs deviate from the WMO (who write the code on behalf of ICAO) FM 15-XII code. Details are listed in the FAA's Aeronautical Information Manual (AIM), but the non-compliant elements are mostly based on the use of non-standard units of measurement. This METAR example is from Trenton-Mercer Airport near Trenton, New Jersey, and was taken on 5 December 2003 at 18:53 UTC.

METAR KTTN 051853Z 04011KT 1/2SM VCTS SN FZFG BKN003 OVC010 M02/M02 A3006 RMK AO2 TSB40 SLP176 P0002 T10171017=^[10]

• METAR indicates that the following is a standard hourly observation.
• KTTN is the ICAO identifier for the Trenton-Mercer Airport.
• 051853Z indicates the day of the month is the 5th and the time of day is 1853 Zulu/UTC, or 1:53PM Eastern Standard Time.
• 04011KT indicates the wind is from 040° true (north east) at 11 knots (20 km/h; 13 mph). In the United States, the wind direction must have a 60° or greater variance for variable wind direction to be reported and the wind speed must be greater than 3 knots (5.6 km/h; 3.5 mph).
• 1/2SM indicates the prevailing visibility is 1⁄2 mi (800 m) SM = statute mile.
• VCTS indicates a thunderstorm (TS) in the vicinity (VC), which means from 5–10 mi (8–16 km).
• SN indicates snow is falling at a moderate intensity; a preceding plus or minus sign (+/-) indicates heavy or light precipitation. Without a +/- sign, moderate precipitation is assumed.
• FZFG indicates the presence of freezing fog.
• BKN003 OVC010 indicates a broken (5⁄8 to 7⁄8 of the sky covered) cloud layer at 300 ft (91 m) above ground level (AGL) and an overcast (8/8 of the sky covered) layer at 1,000 ft (300 m).
• M02/M02 indicates the temperature is −2 °C (28 °F) and the dew point is −2 °C (28 °F). An M in front of the number indicates a negative Celsius temperature/dew point ("minus").
• A3006 indicates the altimeter setting is 30.06 inHg (1,018 hPa).
• RMK indicates the remarks section follows.

Note that what follows are not part of standard observations outside of the United States and can vary significantly.

• AO2 indicates that the station is automated with a precipitation discriminator (rain/snow) sensor.^{[note 1]} Stations that aren't equipped with a rain/snow sensor are designated AO1.^[11]
• TSB40 indicates the thunderstorm began at 40 minutes past the hour at 1840 Zulu/UTC, or 1:40 p.m. Eastern Standard Time.
• SLP176 indicates the current barometric pressure extrapolated to sea level is 1,017.6 hPa (30.05 inHg).
• P0002 indicates that 0.02 inches (0.5 mm) of liquid-equivalent precipitation accumulated during the last hour.
• T10171017 is a breakdown of the temperature and dew point in eight digits separated into two groups of four. The first four digits (1017) indicate the temperature. The first digit (1) designates above or below zero Celsius (0=above zero 1=below zero). The next three digits in the group "017" give the temperature in degrees and tenths of a degree Celsius, −1.7 °C (28.9 °F). The last four digits "1017" indicate the dew point, −1.7 °C (28.9 °F). Note: ASOS software, as of this update, uses whole degrees in °F to compute the °C values in this group.^{[citation needed]}
• = indicates the end of the METAR.

In Canada, RMK is followed by a description of the cloud layers and opacities, in eighths (oktas). For example, CU5 would indicate a cumulus layer with 5⁄8 opacity.^[12]