METAR / TAF Decoder
Enter an airport and get its live METAR and TAF decoded into plain English: wind, visibility, ceiling, and flight category.
Use the 4-letter ICAO identifier (e.g. KJFK, KSFO, EGLL).
What this decoder does
Type an airport identifier and it pulls that field's current observation and its terminal forecast straight from the Aviation Weather Center, then rewrites both in ordinary English: wind in words, visibility in miles, ceiling in feet above the ground, and the flight category the numbers add up to. The raw text stays on screen beside the translation, because the point is to stop needing the translation. If you would rather learn to read it cold, the guide how to read a METAR without decoding it in your head walks the same ground at a slower pace.
How to read a METAR
A METAR is an observation of what the weather is doing at one airport, issued about once an hour, usually near 55 minutes past. It is rigidly ordered, and once you know the order the groups decode themselves because each one looks like nothing else. Reading left to right you get the station, the time, the wind, the visibility, any present weather, the sky, the temperature and dew point, the altimeter setting, and finally the remarks.
A worked example
Here is a routine summer afternoon at New York Kennedy:
KJFK 011651Z 18012G20KT 10SM FEW045 SCT250 27/19 A2992 RMK AO2 SLP131 T02720194
| Group | Means |
|---|---|
| KJFK | New York Kennedy — the reporting station |
| 011651Z | The 1st of the month at 1651 UTC. The first two digits are the day, not the month |
| 18012G20KT | Wind from 180° true at 12 knots, gusting to 20 |
| 10SM | Visibility 10 statute miles, which in a METAR means 10 or better |
| FEW045 | A few clouds at 4,500 ft above the field |
| SCT250 | Scattered cloud at 25,000 ft |
| 27/19 | Temperature 27°C, dew point 19°C |
| A2992 | Altimeter 29.92 inches of mercury |
| RMK AO2 | Automated station that can distinguish rain from snow |
| SLP131 | Sea level pressure 1013.1 hPa |
| T02720194 | Temperature 27.2°C and dew point 19.4°C, to a tenth of a degree |
No ceiling appears anywhere in that report: FEW and SCT are not ceilings. With better than 5 SM and no broken or overcast layer, the field is VFR.
Now San Francisco on a bad morning, where the numbers change the answer:
KSFO 011656Z 28014KT 3SM BR BKN008 OVC015 14/13 A3001
Wind from 280° at 14 knots, 3 statute miles in mist, broken at 800 ft over overcast at 1,500 ft, temperature 14°C with a dew point of 13°C. The ceiling is the lowest broken or overcast layer, so it is 800 ft — and 800 ft with 3 SM is IFR. The one degree spread between temperature and dew point is the tell that the mist is not about to lift.
Sky cover codes
Cloud amount is reported in eighths of the sky, and the height that follows is in hundreds of feet above the airport.
| Code | Cover | Makes a ceiling? |
|---|---|---|
| SKC / CLR | Clear. CLR from an automated station means nothing below 12,000 ft | No |
| FEW | Few — one to two eighths | No |
| SCT | Scattered — three to four eighths | No |
| BKN | Broken — five to seven eighths | Yes |
| OVC | Overcast — eight eighths | Yes |
| VV004 | Sky obscured, vertical visibility 400 ft | Yes |
| CB / TCU | Appended to a layer: cumulonimbus or towering cumulus | — |
Present weather codes
Weather groups are built in a fixed order: intensity, then descriptor, then the phenomenon
itself. So +TSRA is a heavy thunderstorm with rain, -SHSN is light
snow showers, and FZDZ is freezing drizzle.
| Kind | Codes |
|---|---|
| Intensity | - light · nothing moderate · + heavy · VC in the vicinity, 5 to 10 SM out |
| Descriptor | MI shallow · PR partial · BC patches · DR low drifting · BL blowing · SH showers · TS thunderstorm · FZ freezing |
| Precipitation | DZ drizzle · RA rain · SN snow · SG snow grains · PL ice pellets · GR hail · GS small hail · IC ice crystals · UP unknown |
| Obscuration | BR mist (5/8 SM or better) · FG fog (below 5/8 SM) · HZ haze · FU smoke · DU dust · SA sand · VA volcanic ash |
| Other | PO dust whirls · SQ squalls · FC funnel cloud · +FC tornado · SS sandstorm · DS duststorm |
Wind, visibility and temperature notation
| Written | Means |
|---|---|
| VRB05KT | Direction variable at 5 knots — used when the wind is under 6 knots or genuinely shifting |
| 18012G20KT | From 180° at 12 knots gusting 20 |
| 15008KT 120V180 | From 150° at 8, varying between 120° and 180° |
| 00000KT | Calm |
| 1 1/2SM | One and a half statute miles |
| M1/4SM | Less than a quarter of a mile |
| R04R/2000FT | Runway visual range: runway 04R, 2,000 ft |
| M03/M07 | Temperature −3°C, dew point −7°C. M is the minus sign |
How to read a TAF
A TAF forecasts conditions within about 5 statute miles of the airport. It is issued four times a day — 0000Z, 0600Z, 1200Z and 1800Z — covering 24 hours at most airports and 30 at the busiest, and amended whenever the forecast goes wrong. The header carries the issue time and the validity window; everything after it is a sequence of change groups.
A worked example
KJFK 011120Z 0112/0218 18010KT P6SM FEW050
FM011800 21014G22KT P6SM SCT040 BKN120
TEMPO 0120/0123 4SM -TSRA BKN035CB
FM020300 25008KT P6SM SKC
| Line | Means |
|---|---|
| 011120Z | Issued on the 1st at 1120 UTC |
| 0112/0218 | Valid from the 1st at 1200Z to the 2nd at 1800Z. Each half is day then hour |
| 18010KT P6SM FEW050 | To start: wind from 180° at 10, better than 6 SM, a few clouds at 5,000 ft |
| FM011800 … | From the 1st at 1800Z the whole picture changes: 210° at 14 gusting 22, scattered 4,000, broken 12,000 |
| TEMPO 0120/0123 … | Between 2000Z and 2300Z, expect spells of 4 SM in light thunderstorm rain with a broken cumulonimbus deck at 3,500 ft |
| FM020300 … | From the 2nd at 0300Z it clears out: 250° at 8, better than 6 SM, sky clear |
The TEMPO line is the one to plan around. It does not replace the 1800Z forecast; it says that inside that three hour window the field may drop to 4 SM under thunderstorms at any moment, and then come back. If you would be arriving then, you plan for the TEMPO, not for the prevailing line above it.
TAF change groups
| Group | Means |
|---|---|
| FM (from) | A rapid change, inside about an hour. Everything after it replaces the previous conditions completely, so any element it leaves out is genuinely gone |
| BECMG | A gradual change over the stated window, usually two hours. Only the elements listed change; the rest carry over |
| TEMPO | Temporary fluctuations lasting under an hour each and covering less than half the window. A swing on top of the prevailing forecast, not a replacement |
| PROB30 / PROB40 | A 30% or 40% chance of the conditions that follow. US TAFs do not use PROB in the first nine hours |
| WS020/24045KT | Non convective low level wind shear: at 2,000 ft the wind is from 240° at 45 knots |
| NSW | No significant weather — the previously forecast weather ends |
| AMD / COR | The TAF has been amended, or corrected |
What the flight categories mean
The category is a shorthand for the pair of numbers that actually matter, ceiling and visibility, and it is always set by whichever of the two is worse.
| Category | Ceiling | Visibility |
|---|---|---|
| VFR | Greater than 3,000 ft | and greater than 5 SM |
| MVFR (marginal) | 1,000 to 3,000 ft | and/or 3 to 5 SM |
| IFR | 500 to below 1,000 ft | and/or 1 to below 3 SM |
| LIFR (low IFR) | Below 500 ft | and/or below 1 SM |
These are not regulatory minimums. They are a briefing convention for coloring maps and sorting fields quickly. What you may legally do is set by the airspace and by your own personal minimums, which are usually tighter than any of these lines.
Five things that catch people out
- Heights are above the field, in hundreds of feet. BKN008 is 800 ft above the airport, not 800 ft MSL and not 8,000 ft. At a field sitting at 5,000 ft, that layer is near 5,800 ft on your altimeter.
- A low layer is not automatically a ceiling. SCT002 is two hundred feet of scattered cloud and no ceiling at all, so the field can read VFR while you cannot see the threshold. Only BKN, OVC and VV set a ceiling.
- The first two digits are the day. 011651Z is the 1st at 1651Z. A report that looks like it is from a strange month is a report you have misread.
- METAR wind is true, broadcast wind is magnetic. The number in the text and the number the tower reads you differ by the local variation, which matters when you are working out the crosswind component for a runway.
- A TAF is a forecast for a 5 mile circle. It says nothing about the ridge line you cross on the way, and the airport 30 miles down the road has its own. For the picture between fields, use the aviation weather map.
METAR or TAF: which one answers your question
A METAR tells you whether you could depart in the next few minutes. A TAF tells you whether the field will still take you when you arrive, and it is the document the 1-2-3 rule for filing an alternate is read against. Planning a flight normally means both: the METAR to decide whether to start, the TAF at the destination to decide whether to go at all, and the TAF at the alternate to prove the alternate is worth naming.
Where the data comes from
Live observations and forecasts come from the US National Weather Service Aviation Weather Center at aviationweather.gov, the same source the official briefing services read. This page is a planning aid and not an authoritative briefing: get one from Leidos Flight Service or another approved provider before you fly, and treat anything here as a head start rather than a substitute.
FAQ
Which airport code do I use?
Use the four letter ICAO identifier: KJFK (not JFK) for New York Kennedy, KSFO for San Francisco, EGLL for London Heathrow. Most US airports are the three letter FAA identifier with a K in front, but not all — Alaska starts PA and Hawaii PH.
What is the difference between a METAR and a TAF?
A METAR is an observation: what the weather actually is at the field right now, issued about once an hour. A TAF is a forecast: what a meteorologist expects within roughly 5 statute miles of the airport for the next 24 or 30 hours. A METAR reports, a TAF predicts.
How do I find the ceiling in a METAR?
The ceiling is the height of the lowest broken (BKN) or overcast (OVC) layer, or the vertical visibility (VV) when the sky is obscured. Few (FEW) and scattered (SCT) layers are not ceilings however low they sit, so BKN008 is an 800 ft ceiling but SCT008 is not a ceiling at all.
Are cloud heights AGL or MSL?
Above ground level, measured from the airport elevation, and written in hundreds of feet. BKN008 is 800 ft above the field, not 800 ft MSL. Add the field elevation if you need an MSL number.
What does P6SM mean?
More than 6 statute miles. TAFs cap forecast visibility at 6 SM, so anything better is written P6SM rather than a figure. The matching code at the bottom of the scale is M, as in M1/4SM for less than a quarter mile.
Why does the wind in the METAR disagree with the tower?
A METAR or TAF reports wind referenced to true north. A tower, ATIS or AWOS broadcast gives it referenced to magnetic north, because that is what your heading indicator reads. The two differ by the local magnetic variation, which is about 13° on the US east coast and about 12° the other way on the west coast.
Does a TEMPO group replace the forecast?
No. TEMPO describes a condition expected to come and go, lasting under an hour at a time and for less than half the period it covers. The prevailing forecast is whatever the last FM or BECMG group established; TEMPO sits on top of it as a swing you should plan for, not as the new baseline.
What does RMK AO2 mean?
AO2 marks an automated station that can tell rain from snow; AO1 marks one that cannot. Everything after RMK is the remarks section, which is a US practice — sea level pressure as SLP131, precise temperature as T02720194, peak wind as PK WND, and a wind shift as WSHFT.
How often is this page updated?
It reads the live feed from the Aviation Weather Center each time you look up an airport. METARs are issued around 55 minutes past the hour, with a SPECI issued in between when the weather changes sharply. TAFs are issued four times a day, at 0000Z, 0600Z, 1200Z and 1800Z, with amendments as needed.
Is this an official weather briefing?
No. It is a planning aid built on the same FAA and National Weather Service data, and it is not a substitute for an official briefing. Get one from Leidos Flight Service or an approved provider before you fly.
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