SolriseHow to read a METAR
A METAR (Meteorological Aerodrome Report) is a routine weather observation from an airport station, written in compact code. You read it left to right: station, day and time in UTC, wind, visibility, sky condition, temperature and dew point, then the altimeter setting.
What a METAR is
A METAR is a surface observation from an airport weather station: what that station actually measured, not a forecast. It is refreshed roughly once an hour, and more often if conditions change quickly. It is the same real-world data behind everyday weather numbers, just in the compact code aviation has used for decades.
Here is a sample report, decoded below:
KVGT 091853Z 12005KT 10SM FEW150 36/06 A3010
Decoding a METAR, piece by piece
| Code | What it means |
|---|---|
KVGT | Station identifier: the airport's ICAO code. |
091853Z | Day of month and time, in UTC ("Zulu"): the 9th at 18:53 UTC. |
12005KT | Wind: direction in degrees, then speed in knots. Here, from 120 degrees at 5 knots. "VRB" means variable direction. |
10SM | Visibility in statute miles. 10SM is usually the most the station reports. |
CLR, FEW, SCT, BKN, OVC | Sky condition: clear, then increasing cloud cover (few, scattered, broken, overcast), with the cloud base in hundreds of feet. FEW150 is a few clouds at 15,000 ft. |
36/06 | Temperature / dew point, in Celsius. An "M" in front means minus. |
A3010 | Altimeter setting: local barometric pressure in inches of mercury (30.10 inHg here). |
RMK ... | Remarks: extra automated-station detail like pressure trends and precise temperatures. Usually skippable. |
Source: FAA and National Weather Service METAR format.
Sky cover in eighths
| Code | Sky covered | What it looks like |
|---|---|---|
| CLR / SKC | 0 eighths | Clear sky. |
| FEW | 1 to 2 eighths | A few clouds, up to a quarter of the sky. |
| SCT | 3 to 4 eighths | Partly cloudy, up to half the sky. |
| BKN | 5 to 7 eighths | Mostly cloudy, with only gaps of blue. |
| OVC | 8 eighths | The whole sky is covered. |
Source: METAR sky cover categories (oktas).
In aviation, "few" or "scattered" clouds never count as a ceiling. Only a broken or overcast layer does, and the lowest one sets the ceiling.
Why a METAR changes
Each report is a fresh snapshot, so it changes whenever the weather at that station does. The routine report comes out about every hour. When something big changes in between, like a sudden drop in visibility, the station sends an extra report.
What a METAR means for you
Everyday
A METAR is a nearby, frequently updated snapshot of exactly what is happening outside right now. In the example above, 36/06 means 36°C (about 97°F) with a 6°C dew point: hot and dry.
Outdoors
The station may be several miles away and at a different elevation than your trailhead, so treat it as a nearby reference, not the exact conditions where you will be. Check the observation time: it is in UTC.
Flying
METAR wind directions are referenced to true north, while tower and ATIS winds are magnetic, so the numbers can differ. Check the age of the report before you launch; conditions can change well within an hour.
Common questions
What does Z mean in a METAR?
Z stands for Zulu, which means UTC. In 091853Z, the report is from the 9th of the month at 18:53 UTC.
How often is a METAR issued?
Roughly once an hour. When weather changes significantly between routine reports, the station sends an unscheduled special report called a SPECI.
What does M mean in front of a METAR temperature?
M means minus. M05/M10 is a temperature of -5°C with a dew point of -10°C.
Related
See it live in Solrise
Every reading in Solrise Weather comes with its scale, what it feels like, and what it means for your day. Coming soon to the App Store.
See Solrise Weather