Guides
Barometer guides
Short, practical explanations of air pressure, barometers and altitude — with the numbers you actually need.
Basics
What Is Barometric Pressure? A Plain-English Guide
Barometric pressure is the weight of the air above you. Here is what the number means, the units it comes in, what is normal and why it changes with the weather.
Basics
What Is Normal Barometric Pressure?
Normal sea-level pressure is 29.92 inHg (1013.25 hPa). Here are the ranges for high, low and extreme readings, and why the normal at your elevation is lower.
Weather
High vs Low Pressure: What Each Means for the Weather
High pressure usually brings clear, calm weather; low pressure brings clouds, wind and rain. Here is why, with the numbers that separate them and how to tell which one you are in today.
How-to
How to Read a Barometer (and Forecast the Weather)
How to read a dial barometer or barometer app, set it correctly for your elevation and use the rising or falling trend to forecast the next 12–24 hours.