Like a weather station on your wrist, the Suunto Core measures air pressure to help you predict changing weather conditions, from sunny skies to approaching storms. Air pressure is one of the important factors when determining the weather forecast. High pressure is generally connected to good weather. When air descends it becomes warmer, which prevents formation of clouds. In contrast, as air rises it cools. The water carried by cool air condenses into clouds. This is why low pressure is generally associated with bad weather and precipitation. When you’re hiking in a canyon or dense forest without views of the horizon, a Suunto Core can "see" into the distance, keeping you posted of changes in air pressure that can lead to ugly weather. Even at home, a barometer looks beyond office walls, skyscrapers and nearby hills to help you plan for upcoming activities. Short-term trends in barometric pressure can help you decide what to wear (sweater or raingear) and what to do (keep going or head back).