Barometer for Watch vs Pascal Barometer

Pressure and altitude. Beautifully clear. Barometer turns the built-in sensors on your iPhone, iPad and Apple Watch into a clear view of the conditions around you. Check a reading at a glance, follow pressure changes, or explore your altitude as you climb. PRESSURE, IN PERSPECTIVE • Atmospheric and estimated sea-level pressure • Pressure history, trends and changes over time • A pressure-based weather outlook • Optional pressure-change notifications A CLEARER VIEW OF ALTITUDE • Altitude readings and elevation charts • Calibration using a known altitude or available sensor references • Ascent, descent and elevation range • Latitude and longitude • Estimated boiling point of water at the current pressure MADE FOR YOUR DEVICES • A dedicated Apple Watch app • Watch complications and iPhone widgets • Siri and Shortcuts support • Control Center shortcuts • Your choice of measurement units • CSV export for saved measurements Core pressure and altitude measurements work offline using your device’s sensors. Location access enables additional information, including estimated sea-level pressure. Requires iOS 26, iPadOS 26 or watchOS 26. Available readings depend on your device’s sensors and permissions. Pressure-based weather information is an estimate, not an official forecast.

Track atmospheric pressure and predict weather changes using your device's built-in barometer. Pascal transforms your iPhone and Apple Watch into precision barometric instruments. Monitor pressure trends, receive storm warnings, and get weather predictions — all computed on-device with no internet required. FEATURES • Real-time pressure monitoring with 12-hour trend charts • On-device weather forecasting using the Zambretti algorithm • Storm alerts via push notifications • Live Activities showing pressure on Lock Screen and Dynamic Island • Flight mode with cabin altitude tracking • iOS widgets (small, medium, large) and Apple Watch complications • Hybrid calibration system for accurate readings PRIVACY FIRST All data stays on your device. No accounts, no cloud sync, no tracking. Location is used only for GPS altitude calibration and is never stored. TECHNICAL Pascal uses Apple's Core Motion framework to access the barometric sensor, delivering sub-Pascal resolution. The hybrid calibration system combines GPS altitude with relative altitude tracking to filter out elevation changes and surface true weather signals.