METAR (meteorological aeronautical radio code)

A report transmitted by radio of the actual weather at a station at a particular time. An example of such a report for Donlon—a fictitious location—is METAR YUDO 221630Z 24015KMH 0600 R12/1000U FG DZ SCT010 OVC020 17/16 Q1018 BECMG TL1700 0800 FG BECMG AT1800 9999 NSW. It means, the “routine report for Donlon/International (its indicator is YUDO) issued on the 22nd of the month at 1630 UTC (221630Z); surface wind direction 240 degrees, wind speed 15 kmph (24015KMH); visibility 600 m (0600); the runway visual range representing a touchdown zone of runway 12 is 1000 m, and the runway visual range values have shown an upward trend during the previous 10 min (R12/1000U); fog and drizzle (FG DZ); scattered clouds at 300 m (SCT010); overcast at 600 m (OVC020); air temperature 17 °C Celsius, and dew-point temperature 16 °C (17/16); QNH 1018 hectopascals (Q1018); the trend during the next two hours is visibility is becoming 800 m in fog by 1700 UTC (BECMG TL1700 0800 FG); at 1800 UTC, visibility is becoming 10 m or more (BCMG AT1800); and nil significant weather (9999 NSW). UTC is Coordinated Universal Time.