Every abbreviation you are likely to meet in a METAR or TAF, grouped by topic. Use your browser's search (Ctrl+F or Cmd+F) to jump to a code, or paste a whole report into the decoder.
Routine aerodrome weather observation, usually every hour or half hour.
SPECI
Special observation issued between routine reports when conditions change significantly.
TAF
Terminal aerodrome forecast for an airport and its immediate surroundings.
AUTO
Fully automatic observation, no human observer.
COR
Correction to a report that was already issued.
AMD
Amended TAF.
CNL
Cancelled TAF.
NIL
No report available (missing).
RMK
Remarks. National additions at the end of the report, common in US METARs.
Time and units
Z
Zulu time, identical to UTC. There is no daylight saving time in METAR and TAF.
KT
Knots (nautical miles per hour).
MPS
Metres per second.
KMH
Kilometres per hour.
SM
Statute miles, used for visibility in the US and Canada.
hPa
Hectopascal, the pressure unit used with Q (same value as millibar).
inHg
Inches of mercury, the pressure unit used with A.
Wind
24012G25KT
Wind from 240 degrees (true) at 12 kt, gusting 25 kt.
VRB03KT
Variable direction at 3 kt. Used for light winds, or when direction can't be determined.
00000KT
Calm.
190V250
Wind direction varying between 190 and 250 degrees.
WS
Wind shear: a sudden change in wind speed or direction, with the runway affected.
Visibility
9999
Visibility 10 km or more.
0000
Visibility below 50 m.
CAVOK
Ceiling And Visibility OK: visibility 10 km or more, no cloud below 5,000 ft (or the highest minimum sector altitude, whichever is greater), no cumulonimbus or towering cumulus, and no significant weather.
NDV
No directional variation of visibility.
10SM
10 statute miles (US and Canada). P6SM means more than 6 SM.
R27/0600
Runway visual range on runway 27: 600 m. May end in U (increasing), D (decreasing) or N (no change).
Cloud
SKC
Sky clear.
CLR
Clear below 12,000 ft (automated US stations).
NSC
No significant cloud: none below 5,000 ft, no CB or TCU, and CAVOK doesn't apply.
NCD
No cloud detected (automatic station).
FEW
Few: 1 to 2 oktas (eighths of the sky).
SCT
Scattered: 3 to 4 oktas.
BKN
Broken: 5 to 7 oktas.
OVC
Overcast: 8 oktas.
030
Cloud height in hundreds of feet above the airport: BKN030 is broken at 3,000 ft.
VV
Vertical visibility into an obscured sky, in hundreds of feet.
CB
Cumulonimbus (thunderstorm cloud).
TCU
Towering cumulus.
Intensity and proximity
-
Light (for example -RA is light rain).
(none)
Moderate.
+
Heavy (for example +TSRA is a thunderstorm with heavy rain).
VC
In the vicinity: near the airport but not at it (roughly 8 to 16 km).
RE
Recent: happened in the past hour but has ended (for example RERA).
Weather descriptors
MI
Shallow.
BC
Patches.
PR
Partial.
DR
Low drifting.
BL
Blowing.
SH
Showers.
TS
Thunderstorm.
FZ
Freezing.
Precipitation
DZ
Drizzle.
RA
Rain.
SN
Snow.
SG
Snow grains.
IC
Ice crystals.
PL
Ice pellets.
GR
Hail.
GS
Small hail or snow pellets.
UP
Unidentified precipitation (automatic stations).
Obscuration and other phenomena
BR
Mist: visibility 1 to 5 km.
FG
Fog: visibility below 1 km.
FU
Smoke.
VA
Volcanic ash.
DU
Widespread dust.
SA
Sand.
HZ
Haze.
PY
Spray.
PO
Dust or sand whirls.
SQ
Squalls.
FC
Funnel cloud (+FC is a tornado or waterspout).
SS
Sandstorm.
DS
Duststorm.
Trends and forecast groups
NOSIG
No significant change expected in the next 2 hours (appended to some METARs).
BECMG
Becoming: a gradual or regular change to new conditions.
TEMPO
Temporarily: short-lived fluctuations, each under an hour and together under half of the period.
FM
From: rapid change, new conditions from the stated time (FM011800 is day 01, 18:00 UTC).
TL / AT
Until / at the stated time.
PROB30 / PROB40
30% or 40% probability of the conditions that follow.
NSW
No significant weather.
0112/0218
TAF validity or period: from day 01 at 12 UTC to day 02 at 18 UTC.
Pressure
Q1018
QNH 1018 hPa.
A3002
Altimeter setting 30.02 inHg.
QNH
Altimeter setting that makes the altimeter show altitude above mean sea level.
QFE
Pressure at aerodrome elevation: the altimeter reads height above the aerodrome.
Common US remarks (after RMK)
AO1 / AO2
Automated station without / with a precipitation discriminator.
SLP165
Sea-level pressure 1016.5 hPa (the leading 10 or 9 is dropped).
T01780089
Exact temperature and dew point: first digit 0 is positive, 1 is negative. Here +17.8 and +8.9 C.