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

The standard sea level atmospheric pressure is defined as 29.92 inches of mercury (inHg). This value is critical in aviation and meteorology, as it serves as a baseline reference for altimeter settings. The barometric pressure at sea level is influenced by various factors, but 29.92 inHg is the average value used for standard atmospheric conditions.

When pilots set their altimeters for takeoff, they adjust them according to this standard pressure, which ensures accurate altitude readings. Understanding this standard is essential for safe flight operations and navigation, since variations from this standard can affect altitude calculations and aircraft performance.

The other values provided, while they may represent pressures observed in specific conditions, do not correspond to the widely accepted standard for sea level pressure. Therefore, recognizing 29.92 inches of mercury as the standard helps establish a common reference point among pilots and meteorologists.