METAR

A METAR (Meteorological Aerodrome Report) is a routine surface weather observation issued once an hour (with special METARs, or SPECIs, issued between the hourly reports when conditions change significantly). It reports actual, current conditions at the time of observation — wind, visibility, present weather, cloud layers, temperature, dew point, and altimeter setting — in a fixed, internationally standardized coded format.

Cloud layers are reported as coverage plus a three-digit height in hundreds of feet AGL: FEW, SCT (scattered), BKN (broken), or OVC (overcast). The ceiling is defined as the height of the lowest BKN or OVC layer (or vertical visibility into an obscuration) — FEW and SCT layers do not count as a ceiling, which is a common exam trap.

Because a METAR only describes what already happened at the airport, it must be paired with a TAF (Terminal Aerodrome Forecast) for planning ahead, and with AIRMETs or SIGMETs for hazards en route. FAA knowledge tests routinely present a raw METAR string and ask the candidate to decode a specific field, such as wind, visibility, or ceiling.