About METAR and aviation weather

METAR (Meteorological Aerodrome Report) is a standardised format for reporting surface weather at airports. It is defined by the World Meteorological Organisation (WMO) and the International Civil Aviation Organisation (ICAO). Observations are typically issued every 30 or 60 minutes and include wind, visibility, weather phenomena, cloud layers (amount and height), temperature, dewpoint, and pressure (QNH). Pilots use METAR for pre-flight and in-flight decisions (ICAO; WMO; FAA).

Flight categories (VFR, MVFR, IFR, LIFR) are derived from ceiling height and visibility. VFR (Visual Flight Rules) requires ceiling above 3,000 ft AGL and visibility greater than 5 statute miles (or equivalent). MVFR (Marginal VFR) applies when ceiling is 1,000–3,000 ft or visibility 3–5 miles. IFR (Instrument Flight Rules) when ceiling 500–999 ft or visibility 1–3 miles. LIFR (Low IFR) when ceiling below 500 ft or visibility less than 1 mile. These thresholds support consistent operational decisions (FAA; ICAO).

Cloud layers are reported with abbreviations FEW (1–2 oktas), SCT (3–4), BKN (5–7), OVC (8); heights are in feet AGL. Altimeter setting (QNH) is given in hectopascals. METAR is used alongside TAF (Terminal Aerodrome Forecast) and other products. For official aviation weather and flight planning, always use your national aviation authority and approved sources.