What units are used to report current pressure at elevation in METARs?

In METARs, which are aviation routine weather reports, the current pressure at elevation is typically reported in inches of mercury. This unit is widely recognized and used in the United States, aligning with common aviation practices and standards. Using inches of mercury provides pilots and meteorologists with a clear and reliable indication of atmospheric pressure that is crucial for flight operations, navigation, and weather prediction.

While millibars are commonly used in weather reporting internationally, particularly in meteorological contexts outside of the U.S., inches of mercury remain the standard for METARs in the United States specifically for reporting pressure. Other units, such as atmospheres and pascals, are less common within the realm of aviation and are generally not used in METARs, making inches of mercury the correct choice for this question.