METAR (Meteorological Terminal Aviation Routine Weather Report or Meteorological Aerodrome Report) is a format for reporting weather information. A METAR weather report is predominantly used by aircraft pilots, and by meteorologists, who use aggregated METAR information to assist in weather forecasting.
We will learn how to read a METAR in this article.
How can I read METAR?
A METAR has a fixed format. The definition of each part can be found below. Click on the item to jump to the correct paragraph.
METAR/SPECI place day + time COR/AUTO/NIL wind visibility weather clouds temperature air pressure trend
Example:
METAR EYVI 280925Z AUTO 21009G19KT 060V130 5000 -RA FEW007 BKN014CB BKN017 02/M01 Q1001 BECMG 6000
METAR/SPECI
Indicates whether it is a planned sighting METAR or intermediate sighting (SPECI). The SPECI is not much used anymore because most weather stations issue a new observation every half hour.
Place
The ICAO code of the airport / weather station. Usually this is a 4 letter code. Example: EYVI stands for Vilnius Airport.
Day and time
The first 2 digits indicate the day of the month. Followed by the 2 digits of the hour (00-23) and the minutes (00-59). Z is the abbreviation for Zero, time zone 0 is Greenwich Mean Time (UTC). In the NATO phonetic alphabet, the Z is pronounced Zulu, which is why it is also called Zulu time. Note that both the day and time are displayed in UTC / zulu time. This is done to avoid misunderstandings. So 280925Z means the 28th day of the month at 9:25 am UTC.
COR/AUTO/NIL
COR means that this observation replaces a previously drawn up report.
AUTO means that the observation is done automatically. Automatic observations are more limited than manually generated observations.
NIL means that no data is known.
Wind
10009G19KT 060V130 means that the mean wind direction is 100°, variable between 60 and 130°. The average wind speed is 9 knots (09) with peaks up to 19 knots (KT).
- The wind direction and strength are averaged over the last 10 minutes.
- Outliers are only listed if they are 10 knots above average.
- A variable wind direction is only reported if it deviates more than 10° from the mean.
- The wind direction is shown on a scale from 000-350 degrees, rounded to tens of degrees. Where 000 is the north, 090 is the east, 180 is the south and 270 is the west.
- The wind is measured at a height of 33 ft. A METAR therefore does not provide information about high winds, these are usually a lot stronger. This wind information is therefore not useful for navigation.
- In some cases no wind direction is indicated, but for example VRB01KT, namely if:
- The wind speed is 3 knots or less.
- The wind speed is more than 3 knots but varies more than 180°.
- If the wind direction cannot be determined.
- If there is no wind then 00000KT is displayed.
- If both the wind direction and the wind speed cannot be determined /////KT
- The wind speed can be indicated in meters per second (MPS) or miles per hour (MPH) in addition to knots.
Visibility
The visibility shown in the METAR is an average, minimum visibility. 5000 means visibility is 5000 meters. If visibility is less than 1000 meters, the number will be added to 4 characters.
This is to avoid confusion with the imperial system. Visibility can also be indicated in miles or parts thereof: 3SM means the visibility is 3 miles (statute mile). 3/4SM means visibility is 0.75 miles.
- Visibility can be different in different directions. In that case the lowest measured visibility is always displayed. If visibility is only measured in one direction then NDV (Non Directional Variation) is added to the code.
- Visibility can also be listed per direction. 1500SW 2000NE means the visibility to the southwest is 1500 meters and 2000 meters to the northeast.
- In case of poor visibility, the direction can also be displayed per runway. This is also called the RVR (Runway Visual Range). An RVR is usually not reported until visibility is less than 2000 meters. Examples of an RVR:
- R23/0500 visibility for runway 23 is 500 meters
- R23/P0500 visibility for runway 23 is more (P) than 500 meters
- R23/M0500 visibility for runway 23 is less (M) than 500 meters
- R23/0500V1500 visibility for runway 23 varies between 500 and 1500 meters
- R23/0500U visibility for runway 23 is 500 meters but increases (U)
- R23/0500D visibility for runway 23 is 500 meters but decreases (D)
Weather phenomena
-RA means that there is currently light rain This is a combination of RA (rain) and – (light intensity). The codes from the lists below can be combined with each other:
Intensity
| + | heavy |
| – | light |
| RE | recent |
| VC | in the vicinity |
Characteristic
| BC | patches of |
| DR | low drifting |
| MI | shallow |
| PR | partial |
| BL | blowing |
| FZ | freezing |
| SH | showers |
| TS | thunderstorms |
Type
| BR | mist |
| DS | dust storm |
| DU | widespread dust |
| DZ | drizzle |
| FC | funnel cloud |
| FG | fog |
| FU | smoke |
| GR | hail |
| GS | small hail |
| HZ | haze |
| IC | ice crystals |
| PE | ice pellets |
| PO | sand whirls |
| PY | spray |
| RA | rain |
| SA | sand |
| SG | snow grains |
| SN | snow |
| SQ | squalls |
| SS | sand storm |
| UP | unknown precipitation |
| VA | volcanic ash |
Remarks
- The most significant form of precipitation is listed first. Example: GRRA is more hail than rain, RAGR is more rain than hail.
- The intensity and whether it is showery
SHis only used in combination with precipitation. For example when there are showers with heavy rain: +SHRA. - If no intensity is mentioned, it is moderate rainfall.
- MI, BC and PR are only used in fog: ground fog, fog banks and partial aerodrome cover.
- Hypothermic FZ is only used with rain RA, drizzle DZ and fog FG. This means that it will immediately freeze if it comes into contact with a solid surface.
- Low drifting DR and low drifting BL are only used in conjunction with snow SN, sand SA and widespread dust DU.
Differences
- Rain RA or drizzle DZ: drops with a diameter of 0.5 mm or more are rain.
- Fog FG or mist BR: fog is less than 1000 meters visibility.
- Mist BR or haze HZ: if the humidity is more than 80% it is mist.
- Hail GR or small hail GS: with hail the grains are larger than 5 mm.
- Low drifting DR or blowing BL: low wind is less than 2 meters.
Clouds
The cloud cover is listed per layer. Per layer you see:
- The cover in octals (1/8 parts):
- FEW few clouds: 1/8th or 2/8th cover
- SCT scattered clouds: 3/8th or 4/8th cover
- BKN broken clouds: 5/8th to 7/8th cover
- OVC overcast clouds: 8/8th cover
- The height of the bottom of the cloud (cloud base) in hundreds of feet above the airport: FEW007 means a cloud base of 700 ft above site height. If no cloud base can be established, a vertical view can be indicated. For example: VV001 means a vertical view of 100 ft.
- Significant cloud cover: cumulonimbus CB or towering cumulus TCU. Other types of clouds are not mentioned. If the type of clouds cannot be measured, there are 3 slashes behind it. Example: BKN013///.
- Special codes:
- NSC No significant cloud cover. This means that there is no cloud below the 5,000 ft, but there is above it. That cloud cover is not cumulonimbus or towering cumulus.
- SKC No cloud cover (Determined by meteorologist)
- NCD No clouds measured (Automatic weather stations)
- CLR No cloud cover detected below the 12,000 ft (Automatic weather stations)
- OVC overcast clouds: 8/8th cover
Note
Cloud base is also used for the bottom layer of clouds that has a minimum of 5/8 coverage. When we talk about a cloud base of 3,000 ft, we usually mean that there is broken or more cloud from 3,000 ft.
Example
FEW007 BKN014CB BKN017 means three layers of cloud:
- Few clouds at an altitude of 700 ft
- Broken clouds at an altitude of 1,400 ft, with cumulonimbus clouds
- Broken clouds at an altitude of 1,700 ft
The cloud base, broken or more, is then 1,400 ft
CAVOK
CAVOK means that clouds and visibility are okay (“clouds and visibility OK”). CAVOK is a special code, it replaces visibility, clouds and weather. To be CAVOK these conditions must be met:
- Visibility is more than 6¼ mi+
- There is no cloud below the 5,000 ft
- There is no significant cloud cover (cumulonimbus or towering cumulus)
- There is no significant weather
With CAVOK, our example would look a lot shorter. That’s why pilots sometimes jokingly put a yardstick next to the METAR to see if the weather is nice: METAR EHLE 280925Z 21009G19KT 060V130 CAVOK 02/M01 Q1001.
Temperature
Temperature and dew point are always stated in degrees Celsius in a METAR or TAF.
02/M01 means that the temperature is 36 °F and the dew point is 30 °F. Negative numbers are preceded by an M.
Pressure
In the METAR you will also find the air pressure at the mean sea level (QNH). This is calculated by recalculating the air pressure at terrain height (QFE) back to sea level. Air pressure can be expressed in inches of mercury (preceded by an A) or hectopascals (preceded by a Q).
- A2994 means air pressure of 29.94 inHg.
- Q1001 means an air pressure of 1001 hPa.
Trends
At the end of the METAR you will find information about the expected development.
- BECMG is followed by a permanent change in the same coding as earlier in the METAR. For example: BECMG 6000 means that the view will be 3¾ mi.
- TEMPO is followed by a temporary change, less than an hour. For example: TEMPO BKN007 means that there is a temporary cloud layer on 700 ft.
- PROB30 is followed by a change with a probability of 30%. A change with less probability is not mentioned at all. Example: 30% chance that the view is temporary â…› mi: PROB30 TEMPO 0200.
- PROB40 is followed by a change with a probability of 40%. A change with a higher probability is listed without addition.
- FM, TL and AT is followed by a change occurring from, to or on, respectively, said time.
For example: FM1200 6000 means that the view will be 3¾ mi from 12:00 pm.
Military color codes
Military fields often use color codes instead of trends. These color codes summarize the visibility and cloud base. The trend is then displayed in the form of a color code.
GRN AMB TEMPO RED means the color code is now Green, but it will turn Amber for the next 2 hours and will be temporarily Red.
If the code is preceded by BLACK it means that the field is closed. BLACKGRN means a closed field, despite the fact that it would be a code Green again.
| Code | Visibility | Ceiling |
| BLU Blue | > 5 mi | > 2,500 ft |
| WHT White | 3â…› – 5 mi | 1,500 – 2,500 ft |
| GRN Green | 2¼ – 3â…› mi | 700 – 1,500 ft |
| YLO Yellow | 1â…› – 2¼ mi | 300 – 700 ft |
| AMB Amber | ½ mi – 1â…› mi | 200 – 300 ft |
| RED Red | < ½ mi | < 200 ft |
Information about the sea
Weather stations located at sea can report the temperature of the sea water and the height of the waves.
W12/S8 means that it is sea water 54 °F with heavy waves. The height of the waves is indicated from 0 (light) to 9 (heavy).
Wind Shear
If there is wind shear at one or all of the runways:
- WS R23 means that wind shear is reported for runway 23.
- WS ALL RWY means that wind shear is reported for all runways.
Runway conditions
If it has snowed, the condition of the runways can be reported in METAR. A code is then added indicating the type of cover, thickness and braking capacity. For example, this code looks like this: R05/629294.
- R05/ is the runway
- 6 is the type of deposit
- 2 is the covering
- 92 is the thickness
- 94 is the braking capacity
This code means that 11-25% of track 05 is covered with a 10 cm layer of mud and the braking capacity is moderate to good.
These are all codes used:
Type of deposit
| / | not reported |
| 0 | clear and dry |
| 1 | damp |
| 2 | wet or water patches |
| 3 | rime or frost covered |
| 4 | dry snow |
| 5 | wet snow |
| 6 | slush |
| 7 | ice |
| 8 | compacted or rolled snow |
| 9 | frozen ruts or ridges |
Coverage
| / | |
| 1 | from 10% or less |
| 2 | from 11% to 25% |
| 5 | from 26% to 50% |
| 9 | from 51% to 100% |
Thickness
| // | |
| 00 | less than 1 mm |
| 92 | 10 cm |
| 93 | 15 cm |
| 94 | 20 cm |
| 95 | 25 cm |
| 96 | 30 cm |
| 97 | 35 cm |
| 98 | 40 cm or more |
| 99 | closed |
Braking capacity
| 91 | poor |
| 92 | medium/poor |
| 93 | medium |
| 94 | medium/good |
| 95 | good |
| 99 | figures unreliable |
In addition to these codes, there is a special code R/SNOCLO. This means that the field is closed due to snow or ice.
Color codes
The color codes represent the different flight categories. These are derived from the Federal Aviation Administration (FAA) rules. The color codes you see on the site are calculated based on the visibility values ​​and cloud base. These color codes do not tell anything about the temperature, wind, type of clouds and other warnings.
| Code | Visibility | Ceiling |
| VFR Visual Flight Rules | > 5 mi | > 3,000 ft |
| MVFR Marginal VFR | 3-5 mi | 1,000‑3,000 ft |
| IFR Instrument Flight Rules | 1-3 mi | 500‑1,000 ft |
| LIFR Low IFR | < 1 mi | < 500 ft |
Summary
We hope that you found an information you were looking for.
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Last update: 21/12/2021
