A METAR decoder translates a coded aviation weather report into plain English. Paste any METAR into the free decoder below and it explains every group, from wind and visibility to clouds, temperature, altimeter setting and remarks, and labels the report VFR, MVFR, IFR or LIFR. The quick reference after the tool follows the FAA’s Aviation Weather Handbook (FAA-H-8083-28B), so you can also read a METAR on your own when no decoder is handy.
For a complete worked example and what a report means for your flight, read How to Read METARs and TAFs. For the forecast, use the TAF decoder.
The order of a METAR
Every U.S. METAR uses the same sequence, so you always know what comes next. When an element does not occur or cannot be observed, its group is simply left out.
- Type of report: METAR is the routine report, produced near the top of each hour. SPECI is a special report issued between hours when conditions cross set thresholds, such as a thunderstorm beginning.
- Station identifier: the four-letter ICAO code. In the contiguous United States it is K plus the three-letter identifier, so SEA becomes KSEA.
- Date and time: the day of the month, then hours and minutes in UTC, ending in Z. 081753Z is the 8th at 1753 Zulu.
- Modifier: AUTO marks a fully automated report with no human oversight. COR marks a corrected report.
- Wind
- Visibility
- Runway visual range (RVR), when reported
- Present weather
- Sky condition
- Temperature and dew point
- Altimeter setting
- Remarks, after the letters RMK
Wind
The wind group is five digits plus KT. The first three digits are the direction the wind is blowing from, in tens of degrees referenced to true north. The last two are the speed in knots (three digits at 100 knots or more). Both are two-minute averages, so 15014KT is wind from 150 degrees true at 14 knots.
- Gusts: G and the peak gust, as in 27020G35KT. Gusts are reported when the speed varies by 10 knots or more between peaks and lulls.
- Variable at 6 knots or less: VRB replaces the direction, as in VRB03KT.
- Variable above 6 knots: when the direction swings 60 degrees or more, a group such as 180V240 follows the wind.
- Calm: 00000KT.
Runway numbers and the winds you hear from the tower, ATIS, ASOS or AWOS are magnetic, so correct a METAR wind for the local magnetic variation before you run the crosswind component calculator.
Visibility
Visibility is in statute miles, followed by SM. A space separates whole miles from a fraction, so one and a half miles is 1 1/2SM. U.S. automated stations use M for “less than” (M1/4SM is less than a quarter mile), and ASOS and AWOS report 10 miles or more as 10SM. The P prefix (“more than”) appears in the RVR group, and P6SM is a TAF code.
Runway visual range (RVR)
RVR is an instrument-derived value for how far a pilot can see down the runway, in feet. A station with RVR equipment reports it when the prevailing visibility is 1 mile or less, or when the RVR for the designated instrument runway is 6,000 feet or less.
R28L/2600FT: Runway 28L, RVR 2,600 feet.R01L/0600V1000FT: varying between 600 and 1,000 feet.R01L/M0600FT: less than 600 feet, the lowest value the system can report.R27/P6000FT: more than 6,000 feet.
Present weather codes
A weather group is built left to right: intensity or proximity, then a descriptor, then the weather itself. +SHRA is heavy rain showers, -FZDZ is light freezing drizzle, and VCFG is fog in the vicinity. A METAR carries no more than three weather groups, with tornadic activity and thunderstorms listed first.
| Type | Codes |
|---|---|
| Intensity or proximity | - light; no sign moderate; + heavy; VC in the vicinity (5 to 10 statute miles from the point of observation) |
| 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; IC ice crystals; PL ice pellets; GR hail; GS small hail or snow pellets; UP unknown precipitation (automated stations) |
| Obscuration | BR mist; FG fog; FU smoke; VA volcanic ash; DU widespread dust; SA sand; HZ haze; PY spray |
| Other | PO dust or sand whirls; SQ squalls; FC funnel cloud; +FC tornado or waterspout; SS sandstorm; DS dust storm |
- No sign means moderate, except that intensity is never coded for ice crystals (IC) or hail (GR).
- TS by itself is a thunderstorm with no precipitation. In +TSRA the plus sign describes the rain, not the storm.
- FG means fog has cut visibility below 5/8 mile; at 5/8 mile or more the same obscuration is mist (BR). Shallow, patchy and partial fog (MIFG, BCFG, PRFG) are exceptions.
- VC never carries an intensity sign. At automated stations, TS means lightning detected within 5 nautical miles, and VCTS means 5 to 10 nautical miles away.
Thunderstorm, freezing precipitation and fog codes deserve the most attention; our weather hazards guide explains why.
Sky condition and the ceiling
Each layer is a cover code plus a three-digit height in hundreds of feet above ground level, reported from the lowest layer up. BKN025 is a broken layer at 2,500 feet AGL. Amounts are cumulative: each layer includes the sky hidden by the layers below it, which is why the list ends at the first overcast layer.
| Code | Meaning | Sky covered |
|---|---|---|
| SKC | Clear, reported by an observer | 0 |
| CLR | Clear, automated station: no layers detected at or below 12,000 feet | 0 |
| FEW | Few | 1/8 to 2/8 (any amount under 1/8 counts as FEW) |
| SCT | Scattered | 3/8 to 4/8 |
| BKN | Broken | 5/8 to 7/8 |
| OVC | Overcast | 8/8 |
| VV | Vertical visibility into a totally obscured sky (an indefinite ceiling) | 8/8 |
The ceiling is the lowest broken or overcast layer, or the vertical visibility when the sky is totally obscured. BKN025 OVC060 is a 2,500-foot ceiling, and VV002 is an indefinite ceiling of 200 feet. FEW and SCT layers never form a ceiling, and neither does a partial obscuration coded with a height of 000, such as BKN000 (the remarks name the cause, for example FU BKN000 for smoke). At manual stations, CB (cumulonimbus) or TCU (towering cumulus) is attached to the layer, as in OVC010CB.
Temperature, dew point and altimeter
18/12 is a temperature of 18 °C and a dew point of 12 °C, rounded to whole degrees. M means minus, so 04/M02 is 4 °C with a dew point of minus 2 °C, and 02/ means the dew point is missing. A shrinking spread means the air is nearing saturation, and the Aviation Weather Handbook notes that the surface spread is important in anticipating fog. The altimeter setting is A plus four digits in inches of mercury: A2992 is 29.92 (other countries may use hectopascals, as in Q1013). Both numbers feed your density altitude calculation.
Common remarks
Remarks follow RMK. A time in a remark is given in minutes past the hour when it falls in the same hour as the report, and in hours and minutes otherwise.
| Remark | Meaning |
|---|---|
| AO1 | Automated station without a precipitation discriminator (it cannot tell liquid from frozen precipitation) |
| AO2 | Automated station with a precipitation discriminator |
| SLP132 | Sea level pressure 1013.2 millibars. The leading 9 or 10 is dropped, so SLP982 is 998.2. |
| T00261015 | Temperature 2.6 °C and dew point minus 1.5 °C, to the tenth of a degree (a 1 marks a value below zero) |
| PK WND 28045/15 | Peak wind 45 knots from 280 degrees at 15 minutes past the hour (included when the peak wind exceeds 25 knots) |
| WSHFT 30 FROPA | A wind shift began at 30 minutes past the hour, caused by a frontal passage |
| $ | The automated station has detected that it needs maintenance |
Flight categories
The decoder labels each report with the flight category the Aviation Weather Center uses on aviationweather.gov, based on ceiling and visibility. Whichever of the two is worse decides the category.
| Category | Ceiling | Visibility |
|---|---|---|
| VFR | More than 3,000 feet AGL | More than 5 miles |
| Marginal VFR (MVFR) | 1,000 to 3,000 feet AGL | 3 to 5 miles |
| IFR | 500 to below 1,000 feet AGL | 1 mile to less than 3 miles |
| Low IFR (LIFR) | Below 500 feet AGL | Less than 1 mile |
These categories are for situational awareness only. The handbook notes that they are not the basic VFR weather minimums in 14 CFR 91.155, which depend on airspace and altitude (see VFR weather minimums). Student pilots also have a hard floor: 14 CFR 61.89 bars a student from acting as pilot in command with flight or surface visibility below 3 statute miles during daylight hours or 5 at night.
Here is the code list sized for your kneeboard:
- Intensity: - light, no sign moderate, + heavy, VC in the vicinity
- Descriptors: 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, IC ice crystals, PL ice pellets, GR hail, GS small hail or snow pellets, UP unknown
- Obscurations: BR mist, FG fog, FU smoke, VA volcanic ash, DU widespread dust, SA sand, HZ haze, PY spray
- Other: PO dust or sand whirls, SQ squalls, FC funnel cloud, +FC tornado or waterspout, SS sandstorm, DS dust storm
- Sky: SKC or CLR clear, FEW 1/8 to 2/8, SCT 3/8 to 4/8, BKN 5/8 to 7/8, OVC 8/8, VV obscured
- Ceiling: the lowest BKN, OVC or VV layer
- Remarks: AO1 or AO2 station type, PK WND peak wind, WSHFT wind shift, SLP sea level pressure, $ maintenance needed
What you'll need
Keep the code card on your kneeboard and a thorough weather reference in your flight bag.
Frequently asked questions
What does METAR stand for?
The FAA calls it the aviation routine weather report: a coded surface observation that U.S. stations produce near the top of every hour. A SPECI is an unscheduled special report in the same format, issued between hours when conditions change significantly.
Are METAR winds true or magnetic?
True. METAR and TAF wind directions are referenced to true north. Winds from the tower, ATIS, and ASOS or AWOS voice broadcasts are magnetic, the same reference as the runway numbers.
What does M mean in a METAR?
It depends on the group. In temperature and dew point, M means minus, so M05 is minus 5 °C. In visibility and runway visual range, M means less than, as in M1/4SM or R01L/M0600FT.
What is the difference between CLR and SKC?
Both mean no clouds were reported. SKC comes from a station where an observer saw no layers. CLR comes from an automated station and means no clouds were detected at or below 12,000 feet, so higher clouds may still be there.