# Pascal Barometer > Device-based atmospheric pressure tracking and weather forecasting. (iPhone/iPad app by CHRISTOPHER JOHN DILLON.) - Source: https://appshunter.io/ios/app/pascal-barometer/id6759335896 (this page in markdown: same URL + `.md`) - Developer: [CHRISTOPHER JOHN DILLON](https://appshunter.io/developer/1878132185) - Category: Weather, Utilities - Price: Free with in-app purchases - Rating: 5.00/5 from 1 App Store ratings · 2 written reviews indexed - Age rating: 4+ - Requires: iOS 17.0 · 4 MB - Languages: American English - Released: 2026-02-24 - Data updated: 2026-09-01 - Monetization: free with in-app purchases - User reviews in markdown: https://appshunter.io/ios/app/pascal-barometer/id6759335896/reviews.md ## What is Pascal Barometer? 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. ## Key features - Real-time pressure monitoring - On-device weather forecasting - Storm alerts - Live Activities - Flight mode tracking - Widgets and complications ## Pricing and in-app purchases Base price: Free. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | Unlock Widgets | $3.99 | one-time | ## Recent user reviews (2 of 2) All indexed reviews: https://appshunter.io/ios/app/pascal-barometer/id6759335896/reviews.md ### 2/5 — Leider keine 24h Messwerterfassung *2026-07-30* Die App macht zwar einen guten Eindruck, aber leider ist die Luftdruckaufzeichnung in der Nacht trotz deaktiviertem Fokus und Energiesparmodus nicht möglich. Dadurch ist sie leider nicht wirklich brauchbar. **Developer response:** Vielen Dank für das Feedback – und entschuldigen Sie, dass die nächtliche Aufzeichnung bei Ihnen nicht funktioniert. Damit Pascal durchgehend im Hintergrund messen kann, müssen zwei Einstellungen aktiv sein: 1. Einstellungen → Datenschutz & Sicherheit → Ortungsdienste → Pascal → „Immer". Ohne diese Berechtigung erlaubt iOS keine längere Hintergrundausführung, auch bei deaktiviertem Fokus und Energiesparmodus. 2. Einstellungen → Allgemein → Hintergrundaktualisierung → aktiviert (auch für Pascal). Falls es dann immer noch Lücken gibt: In den Einstellungen von Pascal können Sie einen Diagnosebericht senden – schicken Sie mir den gerne, dann schaue ich mir das an. --- In English, in case anyone else has this issue: continuous background recording needs Location Services set to "Always" for Pascal (Settings → Privacy & Security → Location Services), and Background App Refresh enabled (Settings → General → Background App Refresh). Without the "Always" location permission, iOS won't keep the app running overnight regardless of Focus or Low Power Mode. If gaps persist after that, please send a diagnostic report from Pascal's settings and I'll take a look. ### 5/5 — Unique Outstanding Design App! *2026-03-02* Once in awhile you get lucky 🍀 and find an amazing app that not only gives you the confidence of achieving data 📊 that is correct but presented to you in a manner that makes you go WOW! The Developer ( may friends ) has done this in the Hard Work Time Sweat and ya Love into the Coding of this software for you myself and our family. I being an ole man who’s Health has changed to where I must use a cane 🦯 to get around in and the pain I have to endure due to Barometric pressure is an experience I never imagined I would have to endure or face! So this app has helped me to be able to do my walks in the woods to achieve my goal for the day and enjoy Nature! So I want to Thank the Developer for putting out an amazing Unique Outstanding Design 5 Star ⭐️ App! So Mr. Developer I Tip my Hat 🎩 to you and as I walk off using my cane 🦯 I simply want to say “Thanks “ **Developer response:** This is amazing Ron — I’m so so glad to hear it’s been such a help for you! Hope you get some amazing walks in the woods! ## Frequently asked questions about Pascal Barometer ### What is Pascal Barometer? Pascal Barometer is a free weather application that uses your device's built-in barometer to track atmospheric pressure and predict weather changes. It offers on-device forecasting and storm alerts without requiring an internet connection. ### Does Pascal Barometer have ads? No, Pascal Barometer does not contain advertisements. It is a free app with optional in-app purchases. ### What devices does Pascal Barometer support? Pascal Barometer is available for iPhone and Apple Watch. It also supports iOS widgets and Apple Watch complications for quick access to information. ### How accurate is Pascal Barometer's weather forecasting? Pascal Barometer uses the Zambretti algorithm for on-device weather forecasting and features a hybrid calibration system combining GPS and relative altitude tracking for accuracy. The app has a 5.0-star rating from 1 review. ### Can I use Pascal Barometer offline? Yes, Pascal Barometer is designed to work offline. All weather forecasting and pressure monitoring are computed on-device, meaning no internet connection is required. ### What kind of weather alerts does Pascal Barometer provide? Pascal Barometer provides storm alerts via push notifications. It also offers Live Activities to display pressure trends on your Lock Screen and Dynamic Island. ### How often is Pascal Barometer updated? The latest version of Pascal Barometer is 1.5.5, which was last updated on May 30, 2026. This indicates a recent update, suggesting ongoing development and support. ### What is the age rating for Pascal Barometer? Pascal Barometer has an age rating of 4+. This means it is suitable for children aged 4 and older. ## Version history (last 5 releases) ### 1.5.5 — 2026-05-30 Minor UI bug fix with the altitude display. ### 1.5.4 — 2026-05-29 Background refreshes have been tuned for a rock-steady 15-minute cadence — your pressure trace now flows uninterrupted from dawn to dusk, with no mysterious gaps where the barometer went quiet. Storm alerts are yours to shape. Dial sensitivity to Severe for only the serious systems, Moderate for the meaningful shifts, or All to catch every tremor in the atmosphere. Pair it with a daily cap and Pascal will respect your attention — a quiet companion when the sky is calm, a sharper voice when the pressure starts to fall. ### 1.4 — 2026-03-12 Bug Fixes: Fixed: Rapid pressure drops (storms) could permanently block new readings Fixed: Race condition causing missed samples on launch and in background Improved outlier detection that handles extreme weather without false rejections ### 1.3 — 2026-03-12 Weather Forecasting - Improved prediction accuracy and reliability. Altitude Mode - You can now display your altitude over-time - Data points visible on altitude chart for easier reading - Chart toggle moved below the forecast card for cleaner layout Chart Fixes - Fixed axis labels getting cut off on pressure and altitude charts - Improved chart padding for better readability ### 1.2 — 2026-02-24 ### Added - **On-Device Machine Learning**: Personalized weather predictions that learn automatically - **Instant Bootstrapping**: Uses existing pressure history to personalize immediately - **Adaptive Forecasting**: Combines 110-year-old Zambretti algorithm with modern ML - **Overnight Sampling**: Charging-aware background scheduling for better overnight coverage - **Diurnal Correction**: Removes natural daily pressure cycle for more accurate trend detection - **Storm Alerts**: Push notifications for rapid pressure drops and storm conditions - **Live Activities**: Dynamic Island and Lock Screen pressure display (iOS 16.1+) - **Flight Mode**: Cabin pressure tracking with altitude estimation ### Fixed - Background processing tasks now run properly overnight when charging ### How ML Works Pascal learns your local weather patterns automatically — no user action required: 1. **Instant bootstrap** — Seeds model with Zambretti archetypes on first launch 2. **History training** — Walks through existing pressure data to create observations 3. **Auto-evaluation** — After 6 hours, Pascal checks what actually happened 4. **Kernel likelihood** — Similar past conditions inform future predictions **Result:** If you have a week of pressure history, Pascal is personalized immediately. New users reach personalization after ~25 auto-evaluated predictions. All learning happens silently in the background. No feedback buttons needed. --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-01.*