Definition
A continuous broadcast of recorded, non-control information at busier airports, providing arriving and departing aircraft with current airport conditions including active runways, weather (wind, visibility, ceiling, temperature, dew point, altimeter setting), instrument approaches in use, and any pertinent NOTAMs or remarks. Each broadcast is identified by a phonetic letter code (Information Alpha, Bravo, Charlie, etc.) that updates whenever the information changes, typically once per hour or sooner if conditions warrant.
Plain English
A recorded radio message that loops continuously on a set frequency, telling pilots the current airport weather, which runways are in use, and anything else they need to know before talking to ground or tower. Pilots listen to it, then tell the controller which version they heard.
Context Anchor
Pilots usually encounter ATIS before taxiing for departure, before entering an airport’s traffic area, or before contacting approach control or tower near a busy airport.
Derivation
Automatic — it plays on its own without a controller speaking each time. Terminal — refers to the terminal area, meaning the airspace and operations around an airport, not the passenger building. Information — what it provides. Service — a facility provided to pilots. Naming it 'terminal' rather than 'airport' signals that it covers the whole arrival/departure environment, not just the field itself.
Why Pilots Care
Allows pilots to receive up-to-date airport information without congesting the air traffic control radio frequencies.
Analogy
ATIS is like a constantly updated recorded greeting for the airport: before you talk to a person, you listen to the message so you already know the basics.
Intuition Check
Do not read “terminal” here as the passenger terminal building. ATIS is information for aircraft operating near an airport.
Example Sentence 1
Before calling ground for taxi, the pilot tuned in 124.75 and copied down the wind, altimeter, and active runway from ATIS Information Delta.
Example Sentence 2
ATIS updates are issued whenever there is a significant change in weather or runway configuration.