Well, it helps to know a little chemistry ... but the fact that it is falling. Falling air pressure indicates that bad weather is coming, while rising air pressure indicates good weather.

MIKE MOSS SAYS: Margaret, "Hg" in this case comes from the Periodic Table of the Elements, and is the symbol for mercury, because the pressure value shown on the current conditions page is given ...

Today we know this effect ... see a trend toward rising pressure and a northwesterly wind, you might expect generally fair weather to move in, as opposed to a falling barometer and an east or ...

What many anglers know intuitively, but don’t actually understand ... it’s the direction in which the barometric pressure is heading–rising or falling–that has the most significant effect on fishing ...

Some research supports this link between headache and barometric pressure. Some research has suggested that changes in weather, and especially changes in pressure, increase the likelihood of ...

Changes in barometric pressure can cause headaches or pain. If you have ever had a severe headache or migraine episode, you know how debilitating it can be. Not knowing when the next headache is ...

Warm air is lighter and less dense than cold air. High pressure is associated with relatively nice and quiet weather, or sinking air. Low pressure is associated with rising air, clouds ...

Your favorite weather app or website should tell you what the barometric pressure is today in your area. More important than the pressure itself, though, is whether it is rising or falling.