What Does AUTO Mean in a METAR?
AUTO means a fully automated report with no human observer involved. It stands for AUTOmated report.
AUTO in a real report
KABC 121755Z AUTO 21016KT
What it changes for you
AUTO tells you nobody looked at the sky. The measurements are real. They just
cover less of the field than a human observation would.
Three things to hold lightly in an AUTO report:
- Cloud, since the ceilometer only sees what drifts over it
- Visibility, since one sensor cannot scan the horizon
- Thunderstorms, since the station listens for lightning, not thunder
Augmented reports
At some fields an observer augments the sensors, adding what they miss. Those
reports drop the AUTO flag. So no AUTO at a station you know is automated
means somebody was on duty.
Related codes
Decode a report containing this code
Paste a METAR, TAF, PIREP or SIGMET into the WxDecoder decoder. Every group comes back in plain English. The raw code sits beside it, so you can check the decode rather than trust it.
Frequently asked questions
What does AUTO mean in a METAR?
The report was produced by an automated station with no human augmentation. It appears right after the time group. The remarks will usually carry AO1 or AO2 saying which kind of sensor package produced it.
Is an AUTO report less reliable?
Not less accurate, but narrower. An automated station measures cloud with a ceilometer looking straight up and visibility at one point, so isolated cloud and distant phenomena that a human would see may not appear at all.