When I wrote about the hidden sensors on Android phones, the two sensors that stood out the most were a magnetometer that turns your phone into a metal detector and a barometer, which is supposed to improve GPS elevation results. But with the right app, you can use this sensor to predict local weather more accurately than any weather forecast app.
What does the barometer in your phone do?
Measures atmospheric pressure to track weather patterns
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A barometer measures atmospheric pressure, essentially the weight of the air above you. Meteorologists have used barometers for centuries because rising pressure typically means fair weather, while falling pressure often signals rain, snow, or storms approaching. The same principle applies to the tiny sensor inside your phone.
Sure, you can launch your phone’s weather widget or a third-party app to see the forecast. But the barometer sensor on your Android is a fun way to track atmospheric pressure trends yourself. Instead of relying on weather services that predict conditions for your general area, you’re getting real-time data from exactly where you’re standing.
Almost every Android phone made in the last decade includes a built-in barometer. Phone manufacturers include them primarily to improve GPS elevation accuracy. When you’re navigating inside a multi-story building, for instance, your phone uses barometer readings to figure out which floor you’re on. The pressure changes as you move between floors, and the sensor detects these shifts. Emergency services also benefit from this capability since first responders can locate people more precisely inside tall buildings when calling for help.
The digital barometer in your phone works like a traditional aneroid barometer but uses an electronic pressure-sensing transducer instead of mechanical levers. It’s sensitive enough to detect the pressure difference between floors in a building, which means it can certainly pick up the larger pressure swings that accompany weather changes. Since the same sensor can track weather-related pressure changes, you can repurpose it for DIY forecasting with the right app.
Using a barometer app to predict the weather
Track pressure trends and get storm alerts
To read the data from your phone’s barometer sensor, you need an app. While you can use something like Physics Toolbox as an all-in-one sensor suite to read raw data, I find that a dedicated barometer app is more useful for seeing detailed trends over time.
There are plenty of barometer apps on the Play Store, but most are cluttered with ads that make them frustrating to use. I’ve been using Barometer+ Pressure Tracker, a relatively new app that keeps the free version clean without annoying interruptions. It reads data directly from your phone’s sensor, so it works completely offline.
After installing the app, grant it the necessary permissions, and you’ll see a circular gauge showing current pressure. The app supports five different units, including hPa, mmHg, PSI, inHg, and kPa, so you can pick whichever you’re comfortable with. For weather prediction, what matters most is the trend rather than the exact number. If you see pressure steadily climbing over several hours, expect clear skies. If it’s dropping, prepare for possible rain or storms.
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It tracks pressure history with charts that span from 6 hours to 30 days, which helps you spot patterns. You can also enable background monitoring at intervals between 5 and 30 minutes, and set up storm alerts that notify you when pressure drops suddenly. This is the feature I find most useful since a rapid pressure drop often means bad weather is coming within the next few hours. The app lets you adjust notification sensitivity so you’re not bombarded with alerts for minor fluctuations.
For reference, standard sea-level pressure is around 1013.25 hPa or 29.92 inHg. Most weather-related pressure changes happen within a range of roughly 980 to 1040 hPa. A drop of 4-6 hPa over a few hours usually indicates incoming weather, while a slower decline over a day or two suggests a gradual change. Rising pressure typically means improving conditions, though very high pressure sustained for too long can sometimes lead to fog in certain regions.
One thing to keep in mind is that barometer accuracy varies between phone models. Some phones have more precise sensors than others, and the app includes a calibration option to help improve accuracy over time. If you have a Wear OS watch with a pressure sensor, the app can also use your watch as an additional data source.
When barometer readings are most useful
Best for short-term predictions and outdoor activities
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Now, if all you want is an accurate weather forecast, you’re better off using a weather app or your phone’s built-in weather features. They pull data from professional weather stations, satellites, and sophisticated prediction models. A phone barometer can’t compete with that level of analysis for forecasting conditions several days out.
However, barometer readings shine in specific situations. If you’re hiking, fishing, or camping and notice pressure dropping throughout the morning, you’ll know to expect weather changes before they arrive, sometimes hours ahead of a weather app’s notification. Anglers have long used barometer readings because fish feeding patterns tend to change with pressure shifts. And when you’re in areas with spotty cell service, your barometer works regardless of internet connectivity.
The sensor is also useful for tracking altitude when you’re hiking or climbing. Pressure decreases as you gain elevation so that barometer apps can estimate your height above sea level. It’s not as accurate as a dedicated altimeter, but it gives you a rough idea of how much you’ve climbed.
A practical use for a sensor you already have
Most sensors on your phone do far more than you realize, and the barometer is a good example. It’s been sitting there the whole time, quietly helping your GPS figure out which floor you’re on. Using it for weather prediction won’t replace your weather app entirely, but it adds another layer of awareness. If you’ve ever wanted to understand why the pressure readings on your weather app matter, tracking them yourself with your phone’s sensor is a good way to learn.
