Barometers measure air pressure, sometimes explained as the weight of the air pressing down on the earth. This pressure helps determine upcoming weather, and aids in forecasting weather trends. When the barometric pressure is high, it inhibits clouds and rain from forming, leading to generally fair weather. Low barometric pressure allows clouds to form, leading to precipitation of many kinds and poor weather. Barometers often use water in a spout to determine the air pressure; in a basic barometer, if the water level is low, the air pressure is high, whereas if the water is high in the spout, air pressure is low. More advanced barometers use antennas and internal measurements to determine the air pressure, and whether it is rising, falling, or remaining steady. For more information on barometric pressure, be sure to check out our Newsletter Archives.