An aviation routine weather report, or METAR, is an hourly report of local weather conditions in the vicinity of an airport.
These weather conditions include winds, visibilities, weather conditions, cloud coverage and heights, temperature, dew point, and the altimeter setting.
Example: METAR KMKC 121054Z 32022G35KT 2SM -RA FEW012 SCT022 OVC035 09/04 A2978
Type of Report
The first item in the METAR is the type of report. “METAR” indicates a routine report, whereas “SPECI” indicates a special. A special is issued when a rapid
weather change or critical information necessitates a new weather report be issued immediately. Otherwise, a routine report is issued once per hour.
Location Identifier / Date and Time
Next is the location identifier, followed by the date and time.
In this example, this routine weather report for the Kansas City Downtown airport was issued on the 12th day of the month at 1054 Zulu time.
The three digit wind direction, relative to true north, and two digit wind velocity are given next.
The example METAR shows winds from 320 degrees at 22 knots. In this case, the winds are gusting to 35 knots.
Visibility is the greatest distance that can be seen throughout at least 180 degrees of the horizon and is reported in statute miles.
The example visibility is 2 statute miles.
At times of low visibility, where the airport is equipped, runway visual range, or RVR, will be reported, in addition. RVR is reported in feet for a particular
runway. For example, "R5/900FT" would indicate the RVR on runway 5 is only 900 feet.
An "M" prior to the visibility indicates "less than". For example, "M1/4SM" indicates the visibility is less than 1/4 statute mile.
After the visibility, weather conditions are coded using their contractions. The weather conditions include types of precipitation and obscurations.
Types of precipitation include:
- rain (RA)
- snow (SN)
- snow grains
- ice crystals
- ice pellets
- snow pellets
- unknown precipitation (UP)
- mist (BR)
- fog (FG)
- smoke (FU)
- volcanic ash (VA)
- widespread dust
- haze (HZ)
These weather conditions have several descriptors, which are:
- shallow (MI)
- low drifting
- blowing (BL)
- showers (SH)
- thunderstorms (TS)
- freezing (FZ)
Other possible metar weather conditions are:
- dust or sand whirls
- sandstorm (SS)
- dust storm (DS)
- funnel cloud (FC)
If a weather condition is preceded by a minus or plus sign, it is light or heavy, respectively.
For example, +TSRA means thunderstorms with heavy rain. This example weather condition
(-FZRA FG HZ) decodes to mean light freezing rain, fog, and haze.
If "VC" is listed in the weather portion of the METAR, it indicates the weather is between 5 and 10 statute miles from the observation station. For example, "VCSH" means there
are showers between 5 and 10 SM from the station.
In the example METAR, light rain is indicated.
Next is cloud coverage and heights. Cloud coverage is described as few, sct, bkn, or ovc.
- Few means the cloud layer covers 2/8 of the sky or less.
- Scattered means the layers covers 3/8 or 4/8 of the sky.
- Broken clouds cover 5/8, 6/8, or 7/8 of the sky.
- An overcast layer covers 8/8 of the sky.
The three numbers following the sky coverage indicate the height above the ground of the cloud bases, in hundreds of feet. The example metar tells us there are a
few clouds and 1,200 feet above the ground, a scattered layer at 2,200 feet, and an overcast at 3,500 feet.
The lowest cloud layer that is broken or overcast is called the ceiling. In this case, the ceiling is 3,500 feet.
Sometimes overcast skies have no well defined base. When indefinite ceilings exist at an airport, vertical visibility may be reported. For example, "VV003" would indicate
an indefinite ceiling with a vertical visibility of 300 feet.
Temperature and Dewpoint
Temperature and dewpoint are given next, in degrees Celsius. This example shows a dewpoint of nine degrees, with a dewpoint of four.
If the temperature or dewpoint is negative, the negative temperature is preceded by the letter “M”. For example, a temperature of minus 2 with a dewpoint of minus 3 would be
After the temperature and dewpoint comes the altimeter setting. In this example, the altimeter setting is 29.78.
More on the Modifier
Example: KPWM 030612Z AUTO 00000KT 1SM BR OVC001 19/19 A2984
This is the METAR for Portland, Maine, issued on the third day of the month at 0612 Zulu time.
"AUTO” after the date and time indicates the METAR was generated from an automated source.
“COR” may also be placed in this position to indicate a correction to a METAR that was originally issued with an error.
The winds are reported as calm, which is indicated on a METAR by all zeroes for the wind direction and speed. The visibility is one statute mile in mist, with an overcast
ceiling at 100 feet above the ground. The temperature and dewpoint are both 19 degrees, and the altimeter setting is 29.84.
More on the Wind
Example: KAUS 030553Z 31013KT 270V350 10SM CLR 26/14 A3002
The routine weather report for Austin, issued on the third day of the month at 0553 Zulu indicates winds from 310 degrees at 13 knots. The next item says the winds are
variable between 270 degrees and 350 degrees.
Variable wind direction is reported when the wind direction varies by more than 60 degrees and the wind speed is above 6 knots.
The report goes on to state the visibility was ten statute miles, with clear skies, a temperature of 26 degrees, dewpoint of 14, and an altimeter setting of 30.02.
“CLR” in a METAR to indicate an automated weather source reports no clouds observed below 12,000 feet above the ground. If the METAR said “SKC”, it would mean the skies were
manually observed to be clear.
Metars also often have remarks included, such as in this example report from wichita.
Example: KICT 030553Z 16011KT 10SM BKN200 22/15 A2989 RMK AO2 SLP107
After the altimeter setting we are advised that a remark has been added. “AO1” or “AO2” means the remark was generated by an automated system. “SLP” is short for sea level pressure. Sea level pressure is reported in millibars. Since it is always fairly close to 1000 millibars, the sea level pressure is
shortened to the last three digits on the report.
“SLP107” means the sea level pressure was 1010.7 millibars.
“SLP997” would indicate a sea level pressure of 999.7 millibars.
Example: KDEN 030653Z 18010KT 10SM FEW120 19/08 A3007 RMK AO2 SLP092 T01940078
In this example, a sea level pressure of 1009.2 millibars is reported in the remarks.
The numbers that follow are a more precise temperature and dewpoint report, commonly added in the remarks section of METARs. The “T” stands for temperature, followed by
four numbers indicating temperature and four numbers indicating the dewpoint. The first of the four numbers will be a zero if the temperature or dewpoint, as appropriate, is positive and a 1 if the referenced temperature or dewpoint is negative. The next three digits state the temperature or dewpoint to the tenth of a degree.
In this example, the Denver METAR lists the temperature as 19 degrees, with a dewpoint of 8 degrees. The remarks contain the addition that the temperature is positive 19.4 degrees, with a dewpoint of positive 07.8 degrees.
More Example Remarks
Here are a few other examples of remarks that might be seen in a METAR…
- PRESRR: atmospheric pressure is rising rapidly
- PRESSFR: atmospheric pressure is falling rapidly
- VC: the weather described is closer than 10 statute miles away
- DSNT: the weather described is located further than 10 statute miles
- LTG DSNT W: lighting distant west
- OCNL LTGICCG: occasional lightning, in cloud and cloud to ground
- VCSH E: showers in the vicinity to the east
- AO2 TSB25 TS OHD MOV E: automated weather reporting indicates thunderstorm began at 25 minutes past the hour - thunderstorm overhead, moving east
- PK WND 28045/15: peak wind was from 280 degrees at 45 knots and occurred at 15 minutes past the hour
- WSHFT 30 FROPA: wind shift began at 30 minutes past the hour and is associated with frontal passage
- TWR VIS 1/2: tower visibility is 1/2 mile
- FRQ LTG VC: frequent lightning in the vicinity
- LTG DSNT W: lightning distant west
- SHRAB05E30SHSNB20E55: rain showers began at 5 minutes past the hour and ended at 30 minutes past the hour - snow showers began at 20 minutes past the hour and ended at 55
minutes past the hour
- RAESNB42: rain ended and snow began at 42 minutes past the hour
- TSB0159E30: thunderstorm began at time 0159 Zulu and ended at 0230 Zulu
- TS SE MOV NE: thunderstorm southeast moving northeast
- GR 1: hail size is 1 inch
- CIG 005V010: ceilings variable between 500 and 1000 feet above the ground
- CB W MOV E: cumulonimbus clouds to the west moving east
- CBMAM OHD: cumulonimbus mammatus clouds overhead
- SLPNO: sea level pressure not available ("NO" as in "not operating")