METAR Format (FM-15)
Surface Meterological Airways Format
Syntax:
METAR CCCC
TIME AUTO WIND
VISIBILITY WEATHER
CLOUDS TEMP/DEW
ALTIMETER REMARKS
METAR
This defines the product type. This can either be the string "METAR" for a regularly reported observation (such as an hourly) or "SPECI" for a special observation.
CCCC
CCCC is the 4 letter ID uniquely defining the reporting station, for example KORD for O'Hare airport in Chicago.
TIME
The full universal time (UTC) that the observation was taken. The format is:
ddhhmmZ.
dd is the day of the month, hh is the hour, mm is the minute.
AUTO
This is an optional grouping used to specify a station as being automated.
WIND
The wind group
dddssKT or dddssGggKT
The value ddd is the wind direction in degrees. The value ss is the wind speed. The units are defined by the string "KT" which is knots. Some reports may have "MPS" for meters per second. If wind gusts are reported, they are specified with the group "Ggg".
VISIBILITY
The visibility group
vvSM or vvKM
This specifies the visibility is either statue miles "SM" or kilometers "KM". The visibility can be partial values such as "1 1/2SM" or "3/16SM".
WEATHER
The weather group
iiddppooxx
ii is intensity group
| ii | Description |
| - | light |
| moderate | |
| + | heavy |
| VC | in the vicinity |
dd is the descriptor group
| dd | Description |
| MI | shallow |
| PR | partial |
| BC | patches |
| DR | low drifting |
| BL | blowing |
| SH | shower |
| TS | thunderstorm |
| FZ | freezing |
pp is the precipitation group
| pp | Description |
| DZ | drizzle |
| RA | rain |
| SN | snow |
| SG | snow grains |
| IC | ice crystals |
| PE | ice pellets |
| GR | hail |
| GS | small hail/snow pellets |
| UP | unknown |
oo is the obscuration group
| oo | Description |
| BR | mist |
| FG | fog |
| FU | smoke |
| VA | volcanic ash |
| DU | dust |
| SA | sand |
| HZ | haze |
| PY | spray |
xx is the misc group
| xx | Description |
| PO | dust whirls |
| SQ | squalls |
| FC | funnel cloud/tornado/waterspout |
| SS | duststorm |
CLOUDS
The cloud levels
ccchhhtt
ccc is the coverage
CLR or SKC = clear
FEW = 1/8 coverage
SCT = 2,3,4/8 coverage
BKN = 5,6,7/8 coverage
OVC = overcast
VV = vertical visibility for obscuration
hhh is the height of base in 30m or 100ft increments. ie 30 = 3000 feet
tt is an optional type
CU = cumulus
CB = cumulonumbus
TCU = towering cumulus
CI = cirrus
CAVOK = clear skies, unlimited visibility
TEMP/DEW
is the temperature and dewpoint in Celsius
TT/DD
negative values are preceded with a M (M03 = -3)
ALTIMETER
is the altimeter setting
Qpppp = altimeter in whole mb
Apppp = altimeter in .01 in Hg
REMARKS
The remark section:
RMK xxxx xxxx xxxx...
| Remark | Description |
| AO1 | AMOS station |
| AO2 | ASOS station |
| OBS TAKEN +xx | minute offset for observation time |
| SLPppp | Sea level pressure in .1 mb (142 = 1014.2 mb) |
| WEA:www | Additional present weather information |
| Tttttdddd | Current temperature/dewpoint in .1C T01720144 = temp=17.2C, dew=14.4C, first digit 1 for negative |
| 1xxxx | 6 hour max temp in .1C, first digit 1 for negative |
| 2nnnn | 6 hour min temp in .1C, first digit 1 for negative |
| 4/sss | Snow coverage in inches |
| 4xxxxnnnn | 24 hour max/min temps in .1C, first digit 1 for negative |
| 5tppp | Pressure tendency in .1 mb for 3 hours, t is the trend |
| 6pppp | 6 hour precipitation in .01 inches |
| 7pppp | 24 hour precipitation in .01 inches |
| 8/lmh | Cloud type for low, medium, high |
| 933sss | New snow coverage, water equivalent |
| 98mmm | Equivalent sunshine for day in minutes |
| CITY tt | City temperature |
| PCPN pppp Ppppp |
1 hour precipitation |
| PK WND sss/nn | Peak wind, sss is speed, nn is the time |
| PRESFR | Pressure falling rapidly |
| PRESRR | Pressure rising rapidly |
| SNOINCR xxx | Snow increasing rapidly, where xxx is amount of snow in last hour |
| WSHFT nn | Wind shift at time nn |
Examples
| CCCC | TIME | WIND | VIS | WEA | CLOUD | TT/DD | ALT | REMARKS |
| KLAF | 030445Z | 35007KT | 15SM | SKC | 17/13 | A2986 |
KLAF = Station Identifier
030445Z = Time (ddhhmmZ)
35007KT = Winds (350 deg at 7 knots)
15SM = Visibility (15 statute miles)
SKC = Clear skies
17/13 = Temperature/Dewpoint in Celsius
A2986 = Altimieter setting (29.86 in Hg)
| CCCC | TIME | WIND | VIS | WEA | CLOUD | TT/DD | ALT | REMARKS |
| KLAF | 021915Z COR | 22010KT | 7SM | TSRA | BKN055 | 30/17 | A2974 | RMK T W MOVG NE |
TSRA = Weather (TS-Thunderstorm RA-Rain)
BKN055 = Cloud level (Broken at 5500 feet)
| CCCC | TIME | WIND | VIS | WEA | CLOUD | TT/DD | ALT | REMARKS |
| KLAF | 021950Z | 30008KT | 7SM | -RA | BKN065CB | 25/21 | A297 | RMK TE40 |
BKN065CB = Cloud level (Broken at 6500 feet with cumulonimbus)
| CCCC | TIME | WIND | VIS | WEA | CLOUD | TT/DD | ALT | REMARKS |
| LTCC | 022250Z | 32003KT | CAVOK | 24/10 | Q1011 | NOSIG= |
CAVOK = Cloud/Visibility (OK=Clear with unlimited visibility)
Q1011 = Altimeter setting (1011 mb)
| CCCC | TIME | WIND | VIS | WEA | CLOUD | TT/DD | ALT | REMARKS |
| KFHU | 022336Z | 33011G25 | 35SM | TS VCSH | FEW040 SCT060CB BKN100 BKN250 | 31/14 | A3003 | RMK WSHFT 27 FRQ LTGICCG TS N MOV W SHRA N AND NE-SE= |
33011G25 = Winds (330 at 11 Gusts to 25)
TS VCSH = Weather (TS=Thunderstorm, VC=Vicinty, SH=Shower)
FEW040 = Clouds (FEW=few clouds or 1/8 coverage at 4000 feet)
| CCCC | TIME | WIND | VIS | WEA | CLOUD | TT/DD | ALT | REMARKS |
| KIND | 022356Z | 26009KT | 10SM | CLR | 24/20 | A2973 | RMK AO2 SLP062 60000 T02440200 10317 20228 56009 $= |
AO2 = ASOS station
SLP062 = Sea level pressure (062=1006.2 mb)
60000 = 6 hour precipitation (0000=trace)
T02440200 = Current temperature/dewpoint (temp=0244=24.4C,dew=0200=20.0C)
10317 = 6 hour max temp (317=31.7C)
20228 = 6 hour min temp (228=22.8C)
56009 = Pressure tendency (6009=falling .9 mb in last 3 hours)