Generally, if the pressure is falling, the weather is taking a turn towards storms and rain. The starting point of the reading is also important in the forecast. Higher readings indicate better weather even if the pressure is falling.  If the reading is over 30.2 inches of mercury and falling rapidly, this indicates cloudy, but warmer weather. If the reading is between 29.8 and 30.2 inches of mercury and falling rapidly, rain is most likely on the way. If it's under 29.8 inches of mercury and falling slowly, rain is likely; if it's falling rapidly, a storm is imminent. As the air pressure rises, the weather tends to improve as the high pressure systems moves through your location.  Readings over 30.2 inches of mercury that rise indicate that the weather will continue to be fair.  Readings between 29.8 and 30.2 inches of mercury that rise indicate that the weather will remain whatever it presently is. Readings under 29.8 inches of mercury that rise indicate that the weather is clearing, but will be cooler. Steady air pressure indicates long periods of nice weather and suggests that you will be experiencing more of the same. If it's sunny and the pressure is holding, expect more sunshine! Higher pressures indicate warmer weather, while lower pressures indicate cooler weather.  A strong high pressure system is around 30.4 inches of mercury. Anything above 30 is considered high pressure.  A typical low pressure system is around 29.5 inches of mercury. Anything below 29.9 is considered low pressure.
توقع هطول الأمطار عند انخفاض ضغط الجو. تنبّأ بتحسّن الجو عندما يرتفع ضغط الجو. تنبّأ بطقسٍ جيد عند ثبات الضغط الجوي.