METAR decoder

What the METAR decoder shows

A METAR is a coded report of observed weather conditions at an aerodrome. A SPECI is a special observation issued when specified criteria are met. This decoder separates a pasted report into station and observation time, wind, visibility, present weather, cloud layers, ceiling, temperature and dew point, altimeter setting, and decoded remarks when available.

The decoder translates reported groups. It does not fetch weather or determine whether a report is current. The observation time is shown as the day of the month and UTC time because the report itself does not identify the month or year.

How to use the decoder

Paste a complete METAR or SPECI report into the input. The decoded groups update as the report changes, and the input is mirrored in the URL so you can share a particular example. Select Use example to restore the sample report or Clear to remove the input.

A report can include a type and correction marker before the station identifier. The report then identifies the station and observation time, followed by weather groups. Remarks normally appear after RMK. The parser accepts common North American and international formats, but unsupported or malformed groups may prevent a complete decode.

Reading the decoded groups

Wind reports show direction in degrees true, speed, units, gusts, and any variable-direction range. A direction of VRB means variable direction. A calm report is identified separately. Visibility retains the unit and qualifiers such as greater than or less than.

Weather codes describe observed phenomena. For example, -RA means light rain, BR means mist, and VCSH indicates showers in the vicinity. Sky groups describe cloud amount and reported base height. Broken, overcast, and vertical-visibility layers can establish a reported ceiling. The ceiling shown here is the lowest such layer present in the report.

Temperature and dew point are shown in degrees Celsius. The altimeter value retains its reported unit, such as inches of mercury or hectopascals. Remarks can include automated-station information and supplementary observations. Some remarks are not standardized or are not recognized by the parser, so the original remark token remains visible.

Common METAR groups at a glance

The order and presence of groups can vary, and some reports contain additional fields. These examples show common United States report forms:

The observation time gives a day of month and UTC time, not a complete calendar date. Confirm the date and age of a report using the source that provided it. A correction marker or an automated-report marker may also appear, and the format used outside the United States can differ in units and group details.

Common interpretation mistakes

Do not read a METAR as a forecast. It reports conditions at one station at the stated time, while a TAF covers forecast conditions over a specified period. Neither product alone describes every condition along a route.

Reported surface visibility is not the same as flight visibility from an aircraft. Likewise, a reported ceiling is a station observation, not a measurement of cloud separation along a planned path. Use the applicable charts, forecasts, advisories, and regulations as part of a broader weather review.

Example report

The sample METAR KJFK 121651Z 18012G20KT 10SM FEW025 SCT050 BKN100 24/18 A2992 identifies station KJFK and an observation on day 12 at 16:51 UTC. Wind is from 180 degrees at 12 knots, gusting to 20 knots. Visibility is 10 statute miles. The report includes few clouds at 2,500 feet, scattered clouds at 5,000 feet, and a broken layer at 10,000 feet. Temperature is 24 degrees Celsius, dew point is 18 degrees Celsius, and the altimeter setting is 29.92 inches of mercury.

This is an illustrative code example, not a current observation. A METAR only describes conditions reported at its station and observation time. It does not describe conditions along a route or serve as a forecast.

Limitations and verification

Automated decoding can make report groups easier to read, but it cannot replace learning the reporting conventions or checking an official source. The parser may not describe every national variation, uncommon remark, or unsupported code. Always compare an unfamiliar or operationally important group with current official aviation weather references and obtain qualified instruction when needed.

This tool is for training and reference only. A decoded observation is not an operational flight decision. Review current weather, forecasts, advisories, NOTAMs, applicable regulations, and aircraft documentation through appropriate official sources.

For aircraft-specific operating limitations and procedures, consult the applicable POH or AFM. This decoder does not provide those aircraft-specific references.

Sources and methodology

The report format and weather-report guidance are described in the FAA Aeronautical Information Manual, chapter 7. METAR and SPECI data are distributed by the NOAA Aviation Weather Center. The tool parses the user-entered report locally with the metar-taf-parser library and presents its recognized fields. It does not retrieve a live report.

Related tools and resources

• TAF decoder
• Cloud clearance and VFR references
• Airport weather and flight planning