What is the standard measurement for atmospheric pressure at sea level in inches of mercury?

The standard measurement for atmospheric pressure at sea level is 29.92 inches of mercury, which is accepted as the average barometric pressure under standard conditions. This measurement is derived from the calibration of mercury barometers, which have historically been used to measure atmospheric pressure. At sea level, under normal conditions, this value is consistent and serves as a reference point for various meteorological and navigational calculations.

Understanding this standard allows sailors and navigators to assess weather patterns and changes in atmospheric pressure, which can be crucial for safety and navigation. The other values listed do not accurately reflect the standardized measurement at sea level and could result in misjudgments regarding weather conditions if used as a reference.