METAR vs TAF vs SPECI

These three products use the same weather code, which is why they get confused. The difference is what they describe and when.

	METAR	SPECI	TAF
What it is	A routine observation: what is happening now	A special observation when conditions change significantly	A forecast
Time covered	The moment of observation (some add a 2-hour trend)	The moment of observation	Typically 9 to 30 hours ahead
How often	Usually every 30 or 60 minutes (some airports every 3 hours)	Only when needed, between METARs	Usually every 3 to 6 hours
Best for	Current conditions and recent trends	Spotting sudden changes	Planning, alternates and timing

Which one should you look at?

Departing within the hour: the latest METAR, with a glance at the TAF.
Planning a flight a few hours ahead: the TAF, then check how the METARs compare as the time approaches.
The weather looks different from the forecast: trust the newest METAR or SPECI.

SIGMET: a warning of significant en-route weather such as thunderstorms, turbulence or icing.
AIRMET: a US advisory for hazards that matter to lighter aircraft, such as low visibility or moderate icing.
PIREP: a pilot report of weather actually encountered in flight.

See real reports: EGLL · KJFK · EDDF · EPWR · all airports.

Educational material. It does not replace flight training or an official weather briefing.