weather term
Barometric Pressure
The weight of the atmosphere pressing down at a given location, measured in units such as hectopascals or inches of mercury.
Falling pressure usually signals that a low-pressure system, and the unsettled, wetter weather that comes with it, is approaching. Rising pressure, by contrast, typically points toward calmer, clearer conditions. Meteorologists track pressure changes over time rather than a single reading, since the rate of change often says more about incoming weather than the absolute number itself.