Apple has released the official watchOS 27 release notes ahead of next week's launch alongside the Apple Watch Series 12 and Apple Watch Ultra 4. The update brings a significantly upgraded Siri AI with personal context understanding, onscreen awareness, and a dedicated app that syncs conversations via iCloud. New expressive voices and customization options are available on paired iPhone Air and iPhone 17 Pro models and later.

Apple Intelligence expands across apps with Workout Buddy now functioning without a nearby iPhone via Wi-Fi or cellular. Call Context in the Phone app proactively surfaces relevant info like confirmation codes. Cycle Tracking adds perimenopause deviation notifications for users 40 and over.

New watch faces include the Siri Modular face with a dynamic Smart Stack widget mirror and Siri complication. Smart Stack gains a single-handed tap gesture (index finger to thumb) for widget selection and new suggestion widgets for parked car location, birthday reminders, transit card balances, and Noise alerts. System improvements feature a dynamic app grid, consolidated Find My app, faster media playback, more accurate treadmill distance calculations and route maps, proactive battery extension notifications, and offline Shazam music recognition. Liquid Glass refinements improve readability.