METAR is the international format for reporting current surface weather observations at aerodromes. This guide is written for beginners who want a clear, practical walkthrough, with a short historical note, essential tips, and a detailed, step‑by‑step decoding of a realistic example METAR string. The tone remains mostly formal and educational; when appropriate you’ll find short friendly notes to keep things approachable.
What is METAR? (Short)
A METAR is a standardized weather report issued at regular intervals (usually hourly) and whenever significant changes occur. It summarizes wind, visibility, weather phenomena (rain, snow, fog), cloud layers, temperature/dewpoint, pressure, and special remarks. Pilots, dispatchers, and enthusiasts use METARs to get a snapshot of current conditions at an airport.
A brief history of METAR
METAR has been developed and standardized by the World Meteorological Organization (WMO) and adapted by national aviation authorities over many decades. Its compact, machine‑readable format grew from the need to transmit essential meteorological information efficiently over radios and telex systems. Although communication methods evolved, the METAR string remained because of its precision and global interoperability.
How to approach reading a METAR (concise)
Rather than memorizing every rule first, learn to read a full example end‑to‑end — that will help you recognize tokens by context. METAR tokens are ordered logically: station identifier, time, wind, visibility, weather, sky condition, temperatures, pressure, and remarks. Below we decode a full example token by token so you can see the practical meaning.
Example METAR (fictional for learning purposes)
METAR WIII 041500Z 22012G22KT 7000 -RA BKN018 OVC040 26/24 Q1007 NOSIG RMK A02 SLP987
We will decode this exact string step‑by‑step. Treat this as a template you can apply to other METARs.
Decoding — step by step (each token explained in its own paragraph)
METAR — This indicates the report type. A routine observation is labeled METAR. If it is a special report issued between routine observations because conditions changed significantly, it would be labeled SPECI.
WIII — The four‑letter ICAO station identifier for the reporting aerodrome. WIII is the ICAO code for Soekarno‑Hatta International Airport (Jakarta). Every METAR begins with this identifier so you know which airport the report refers to.
041500Z — Date/time group. 04 is the day of the month, 1500 is the time in UTC (also written as Z or Zulu time). So this reads as the 04th day at 15:00 UTC. Always interpret this in UTC, not local time.
22012G22KT — Wind group. 220 is the wind direction in degrees true (from 220°). 12 means mean wind speed 12 knots. G22 indicates gusts to 22 knots. KT is the unit (knots). If wind were variable or calm, the group would show VRB or 00000KT depending on conditions.
7000 — Horizontal visibility in meters. In ICAO format, visibility is commonly given in meters; 7000 means 7,000 meters (7 km). In some countries or older reports, visibility might be given in statute miles or in runway visual range (RVR) for low visibility conditions.
-RA — Present weather. The – sign is an intensity modifier (- = light, no sign = moderate, + = heavy). RA is rain. So -RA means light rain at the time of observation. Other common abbreviations include SN (snow), FG (fog), TS (thunderstorm), and DZ (drizzle).
BKN018 — Cloud coverage and base. BKN stands for broken clouds (5/8 to 7/8 sky coverage). 018 gives the base height of that layer in hundreds of feet above ground level: 018 → 1,800 ft. This token tells you there is a broken cloud layer at approximately 1,800 ft.
OVC040 — Another cloud layer token: OVC means overcast (8/8 coverage) with base at 040 → 4,000 ft. METARs list cloud layers from lowest to highest when present.
26/24 — Temperature and dew point in degrees Celsius. 26°C is the air temperature, 24°C is the dew point. When temperature and dew point are close, humidity is high and the air is near saturation — important for fog, icing, and thunderstorms.
Q1007 — Altimeter setting (pressure) in hectopascals (hPa) / millibars. Q1007 means sea‑level pressure of 1007 hPa. In the U.S., you’ll often see A2992 (in inches of mercury) instead; Q is the international convention (QNH in hPa).
NOSIG — A routine remark meaning “no significant change expected” in the near term. It’s often appended when conditions are expected to remain stable for a short forecast window. Other remarks might indicate expected changes, temporarily reduced visibility, or phenomena of operational importance.
RMK A02 SLP987 — Remarks (RMK). A02 indicates the automated station has precipitation sensor capability (this is station‑specific metadata). SLP987 gives sea level pressure of 998.7 hPa (read as the last three digits with an assumed leading 9 or 10 depending on value). Remarks may contain runway state, recent weather events, or sensor flags.
Key practical notes (short paragraphs)
METAR vs TAF: METAR reports current conditions. A TAF (Terminal Aerodrome Forecast) is the forecast counterpart and should be consulted for expected conditions over the next 6–30 hours. Use METAR for the latest snapshot; use TAF to anticipate changes.
Units and conventions: Wind is in knots, direction in degrees true. Visibility in meters (ICAO) or statute miles (in some FAA products). Temperature in °C in ICAO products. Pressure usually appears in hPa with a leading Q (e.g., Q1013). Always check which convention the provider uses.
SPECI and automated reports: A SPECI is issued when significant conditions change between regular METARs. Automated stations may include an AUTO token and can sometimes generate METARs without human verification — those METARs may miss some subtle phenomena that a human observer would note.
Common abbreviations cheat‑sheet (very short):
RA = rain, DZ = drizzle, SN = snow, FG = fog, BR = mist (brume), TS = thunderstorm.
SKC / CLR = sky clear, FEW = few (1–2 oktas), SCT = scattered (3–4 oktas), BKN = broken (5–7 oktas), OVC = overcast (8 oktas).
Intensity signs: – light, (no sign) moderate, + heavy; SH = showers, DR = low drifting.
Why this matters for pilots and aviation enthusiasts
METAR provides immediate operational information: crosswind and gusts from the wind group, whether visibility or cloud ceilings are below approach minima, whether precipitation or icing is present, and runway contamination hints from remarks. Learning to read METARs quickly is a valuable safety skill and improves situational awareness.
Quick practice tips
- Start by identifying the station and time so you’re sure the report is for the aerodrome and time you expect.
- Scan wind and visibility first — they often determine go/no‑go decisions. Then check cloud ceilings and present weather. Finally, note temperature/dew point and remarks.
- Practice by decoding five METARs from different airports each week — try to explain each token out loud or in writing.
That’s the core of reading METARs for beginners. Thank you for read this article.