What units are used for reporting Sea-Level Pressure?

Sea-level pressure is primarily reported in units of hectopascals (hPa) in meteorological practices. The hectopascal is a convenient unit within the International System of Units (SI) and is equal to 100 pascals. In weather observations, especially those that comply with international standards, using hectopascals provides a consistent and easily interpretable measure of atmospheric pressure.

While inches of mercury and millibars are also recognized units for pressure measurement, hectopascals have become the standard for reporting in modern meteorology, especially in contexts like aviation and meteorological reports. The transition toward using hectopascals aligns with global practices that favor metric units for scientific accuracy. Centimeters of mercury, while a legitimate measure historically, are not commonly used in contemporary meteorological data.

Thus, the use of hectopascals ensures clarity and consistency in communication among meteorological organizations and is the preferred unit for reporting sea-level pressure.