What does 'AUTO' in an ASOS report signify?

'AUTO' in an ASOS report signifies that the meteorological data has been collected through automated observation systems. This indicates that the report generated is based on measurements taken without human intervention, ensuring a high frequency of data collection and real-time reporting. Automated systems are designed to monitor and record atmospheric conditions such as temperature, humidity, wind speed, and precipitation, providing reliable and consistent weather information. The use of automated systems helps in maintaining objectivity in weather reporting, as they reduce the likelihood of human errors and biases in data collection. This allows for a continuous and accurate view of weather conditions, which is critical for various applications, including aviation and local weather forecasting.