Decoding METAR/TAF
and Temperature & UTC Conversions

Decoding TAFs

Decoding METARs

Element	Example(s)	Explanation
Type of Report	METAR	METAR or TAF
ICAO Location Identifier	K4B0	As an example, what a report filed from South Albany would look like
Date/Time Block	170955Z	Issuance time: ALL times in report are UTC "Z" 2-digit date 4-digit time (no month)
Comments	AUTO	In U.S. METAR, CORrected observation or AUTOmated observation for automated report with no human intervention; omitted when observer logs on
Wind	32015G25KT	3 digit true-north direction, nearest 10 degrees or VAR (i.e., VaRiaBle) 2-3 digits for speed and unit, KT (KMH or MPS) as needed, Gust and maximum speed; 00000KT for calm; if direction varies 60 degrees or more, Variability appended, e.g. 180V260
Prevailing Visibility	4SM	in U.S. METAR, Statute Miles & fractions above 6 miles Plus6SM (i.e., P6SM), OR 4-digit minimum visibility in meters [?] and, as required, lowest value with direction
Runway Visual Range	R19/2200FT	R 2-digit runway designator (Left, Center, or Right) "/" Minus or Plus in U.S METAR 4-digit value, FeeT in U.S METAR (usually meters elsewhere); OR 4-digit value Varialble 4-digit value (and tendency Down, Up or No change)
Significant Present, Forecast and Recent Weather	TSRA	see table below (as shown, "thunderstorm and rain")
Cloud Amount, Height and Type	OVC010CB	Sky Condition: SKC SKy Clear • 0/8 cloud cover FEW FEW • >0/8-2/8 cloud cover SCT SCaTtered • 3/8-4/8 cloud cover BKN BroKeN • 5/8-7/8 cloud cover OVC OVerCast • 8/8 cloud cover 3-digit height in hundreds of feet Towering CUmulus or CumulonimBus (cf. TAF) Vertical Visibility for obscured sky and height, e.g., "VV004" More than 1 layer may be forecast In automated METAR reports only, CLeaR for "clear below 12,000 feet" (SKC, in manual reports only, indicates no layers are visible at any altitude)
Temperature: Degrees Celsius	18/16	First 2 digits, temperature "/" last 2 digits, dew-point temperature Minus for below zero, e.g., M06 See Conversion Utility below
Altimeter Setting	A2992	Indicator and 4 digits in U.S., A = inches and hundredths otherwise, Q = hectoPascals, e.g. Q1013
ReMarK indicator & remarks	RMK AO2 SLP045 T01820159	For example, • "A02" means that the site is automated and HAS a precipitation sensor    "AO1" means there is no precipitation sensor • Sea-Level Pressure in hectoPascals & tenths (as shown, 1004.5 hPa) • Temp/dew-point in tenths ° C (as shown, temperature 18.2°C, dew-point 15.9 ° C); negative temperatures expressed as 100 degrees

• See Periodic Additional Data & WMO Codes for additional code explanations, including decoding observations in the METAR remarks section.

Table of Significant Present, Forecast, and Recent Weather

Grouped in categories and used in the order listed below; or as needed in TAF.

• See Periodic Additional Data & WMO Codes for additional code explanations.

References:

"Key to Aerodrome Forecast (TAF) and Aviation Routine Weather Report (METAR)," National Oceanic and Atmospheric Administration (NOAA), retrieved 15 October 2012.

Federal Aviation Administration (FAA):

• Aviation Weather, Advisory Circular (AC) 00-06A, available at FAA Advisory Circulars
• Aviation Weather Services, Advisory Circular (AC) 00-45G, available at FAA Advisory Circulars

The Federal Meteorological, Handbook No. 1, Office of the Federal Coordinator for Meteorology, retrieved 10 March 2014.

World Meteorological Organization (WMO):

• Manual on Codes - International Codes, Volume I.1: part A- Alphanumeric Codes
• Manual on Codes - International Codes, Volume I.2: Part B and Part C

• Volume I contains WMO international codes for meteorological data and other geophysical data relating to meteorology; it is issued in two volumes: Volume I.1, containing Part A, and Volume I.2, containing Parts B and C.
• Volume II contains, for the six WMO Regions and the Antarctic, the procedures for the use of international code forms as well as regional code forms and national coding practices, including national code forms.

Types of Automated Systems

Automated Weather Observing System (AWOS)

AWOS is a modular system utilizing a central processor that receives input from multiple sensors. The standard sensor configurations are defined below:

• AWOS A: Dual-pressure sensor measures pressure and reports altimeter setting
• AWOS I: Wind Speed & Wind Gusts in knots, Wind Direction, Variable Wind Direction, Temperature & Dew Point in degrees Celsius, Altimeter Setting, and Density Altitude
• AWOS II: Same as AWOS I plus Visibility, Variable Visibility, Precipitation, Day/Night
• AWOS III: Same as AWOS II plus Cloud Height & Sky Condition
• AWOS III-P: Same as AWOS III plus Present Weather Identification Sensor
• AWOS III-PT: Same as AWOS III plus Present Weather & Lightning Detection
• AWOS III-PTZ: Same as AWOS III plus Present Weather & Lightning Detection, Freezing Rain Detection

Automated Surface Observing System (ASOS)

ASOS generally report all the parameters of the AWOS-III, while also having the additional capabilities of reporting the following:

• Temperature and Dew point in degrees Fahrenheit
• Present Weather
• Lightning
• Icing
• Sea Level Pressure
• Precipitation Accumulation

Automated Weather Sensor System (AWSS)

AWSS is a follow-on to the FAA's AWOS program. The reporting characteristics of the AWSS are very similar to those of ASOS, and includes the following components:

• Forward Scatter Visibility Sensor (capable of measuring fog, dust, rain, snow, haze, smoke, and sand)
• Ceilometer
• Present Weather Sensor
• Wind Speed Sensor
• Wind Direction Sensor
• Freezing Rain Sensor (detects an occurrence of freezing rain by the change in the probe tip's oscillating frequency caused by ice accretion)
• Tipping Bucket Rain Gauge: precision sensor used to measure rainfall volume or rate
• Temperature & Relative Humidity Sensor

Specifically as listed in the Airway/Facility Legend

AWOS Automated Weather Observing System:

AWOS A

reports altimeter setting (all other information is advisory only).

AWOS AV

reports altimeter and visibility.

AWOS 1

reports altimeter setting, wind data and usually temperature, dew point and density altitude.

AWOS 2

reports the same as AWOS 1 plus visibility.

AWOS 3

reports the same as AWOS 1 plus visibility and cloud/ceiling data.

AWOS 3P

reports the same as the AWOS 3 system, plus a precipitation identification sensor.

AWOS 3PT

reports the same as the AWOS 3 system, plus precipitation identification sensor and a thunderstorm/lightning reporting capability.

AWOS 3T

reports the same as AWOS 3 system and includes a thunderstorm/lightning reporting capability.

AWOS 4

reports same as AWOS 3 system, plus precipitation occurence, type and accumulation, freezing rain, thunderstorm, and runway surface sensor.

ASOS

Automated Surface Observing System. Reports the same as an AWOS 3 plus precipitation identification and intensity, and freezing rain occurrence.

References:

"Automated airport weather station," Wikipedia, retrieved 15 October 2012.

"Automated Weather Observing System (AWOS)," All Weather, Inc., retrieved 15 October 2012.

The Federal Meteorological Handbook No. 1, Office of the Federal Coordinator for Meteorology, retrieved 15 October 2012.

Airway/Facility Directory, Federal Aviation Administration, retrieved 15 October 2012.

Temperature Conversions

Type in a value in the Input field;
for output, press <enter>, <tab>,
or mouse-click anywhere outside the input box.
(Actually, if you enter in the output field it works, too.)

[ Notes on Temperature Scales ]

[ All kinds of other converters and calculators ]

UTC Cross Reference

To/From North American & Other United States Time Zones

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