Definition
A ground-based system of sensors installed at or near an airport that automatically measures local weather conditions — such as wind speed and direction, visibility, cloud height, temperature, dew point, and altimeter setting — and broadcasts the information continuously over a dedicated radio frequency or telephone line.
Plain English
A set of automatic weather instruments at an airport that measure the local weather and read it out loud over the radio so pilots can hear the current conditions before landing or taking off.
Context Anchor
Pilots commonly use it before takeoff, before landing at an airport without a staffed weather observer, and while planning whether the current weather is suitable for the flight.
Derivation
Automated comes from an older Greek idea meaning “acting by itself.” Observing means watching or measuring. Together, the phrase points to a system that measures airport weather by itself instead of relying on a person to make each report.
Why Pilots Care
Provides reliable, real-time weather data at remote or unattended fields, reducing the need for manual checks and supporting safer go/no-go decisions.
Intuition Check
Do not read this as a forecast. An Automated Weather Observing System reports current conditions at that airport; it does not predict what the weather will be later.
Example Sentence 1
Ten miles out, the pilot tuned in the AWOS to get the current wind and altimeter setting before entering the traffic pattern.
Example Sentence 2
Many small airports rely on an Automated Weather Observing System to give pilots continuous updates when no weather briefer is available.