Meteorological Aerodrome Report (METAR)

Definition

A METAR is an aviation weather report that provides the current, observed meteorological conditions at an aerodrome. It is updated every hour (routine METAR), or as needed (special METAR – SPECI), and is used by pilots, dispatchers, and air traffic controllers for real-time weather assessment.
METARs are essential for preflight planning, in-flight updates, and runway and approach decision-making.

Purpose

Inform pilots of actual conditions at departure, enroute alternate, and destination airports
Support decisions on VFR vs. IFR, fuel planning, and alternate selection
Aid ATC in assigning runways and approach types
Evaluate if conditions meet landing/takeoff minima

METAR Format Overview

A standard METAR includes:

Aerodrome ICAO identifier
Time of observation (UTC)
Wind speed and direction
Visibility
Significant weather phenomena
Cloud layers and coverage
Temperature and dew point
QNH (sea-level pressure)
Runway condition reports (optional)
Recent weather changes and trends

Example METAR

LOWW 081250Z 28010KT 9999 FEW020 SCT040 BKN080 17/10 Q1013 NOSIG

Decoded:

LOWW: Vienna International Airport
081250Z: Observed on the 8th at 12:50 UTC
28010KT: Wind from 280° at 10 knots
9999: Visibility 10 km or more
FEW020 SCT040 BKN080: Few clouds at 2000 ft, scattered at 4000 ft, broken at 8000 ft
17/10: Temperature 17°C, dew point 10°C
Q1013: Pressure 1013 hPa
NOSIG: No significant weather change expected in next 2 hours

METAR Components

Code	Meaning
KT	Wind speed in knots
9999	Visibility ≥10 km
FEW/SCT/BKN/OVC	Cloud coverage levels
RA/SN/TS	Rain, snow, thunderstorm
QNH/QXXXX	Atmospheric pressure at sea level
NOSIG	No significant changes expected
CAVOK	Ceiling and visibility OK (≥5,000 ft, no weather)
SPECI	Special report issued for sudden weather change

METAR vs. TAF

Feature	METAR	TAF
Type	Observation	Forecast
Frequency	Hourly (or as needed)	6–8 hours, valid up to 30 hours
Use	Real-time flight decisions	Planning and alternate selection
Format	Static snapshot	Predictive sequence

Why METARs Matter

✅ Provide a reliable snapshot of current flight conditions
✅ Help verify actual weather matches or deviates from the forecast
✅ Allow pilots to evaluate departure and destination safety
✅ Support fuel and alternate decisions, especially under IFR

Phraseology Examples

“Wien Tower, copied latest METAR: visibility 3000 meters, broken clouds at 900 feet.”
“METAR indicates wind 220 at 12 knots, request runway 22.”

Pilot Tips

Always compare latest METAR and TAF
Use “CAVOK” to quickly assess favorable VFR conditions
Check for wind shifts, low clouds, or pressure drops indicating change
Practice reading raw METARs with LearnATC training tools