What is the standard atmospheric pressure at sea level?

The standard atmospheric pressure at sea level is defined as 29.92 inches of mercury. This measurement is a standard used in meteorology and aviation to establish a reference point for measuring pressure. This value is significant because it allows pilots and meteorologists to compare atmospheric conditions and ensures consistency when measuring altimeter settings across different regions and weather situations.

Using 29.92 inches of mercury also aligns with other units of pressure measurement, such as 1013.25 hPa (hectopascals) or 1013.25 mb (millibars), which are commonly used in aviation and meteorological contexts. Understanding this standard pressure is crucial for accurate altitude readings, as pressure decreases with altitude, and the altimeter relies on this baseline value to provide correct altitude information.