How long is a METAR valid?

• A. Only valid at time of observation; not a forecast
• B. Valid for 6 hours
• C. Valid for 12 hours
• D. Valid for 24 hours

Answer: (A)

METARs are weather observations tied to a single moment in time. They capture the conditions at the aerodrome at the exact moment of observation and are not intended to forecast what will happen next. Because of that, a METAR is considered valid only at the moment it’s reported; as soon as a new observation is made, the previous report is superseded. If you want a forecast that covers a period, you’d look at a TAF, which is valid for 24 hours and may be amended. Other durations like six, twelve, or twenty-four hours correspond to forecast products, not METARs.