watchOS 27 arrives as a free update on Monday, September 14, 2026, and Apple lists eight Apple Watch models that can install it: Apple Watch SE 3, Series 9, Series 10, Series 11, Series 12, Ultra 2, Ultra 3 and Ultra 4. Five recent models are absent from that list, including Series 8 and the original Apple Watch Ultra.
The update is also tied to the phone in your pocket. Apple’s watchOS page states that watchOS 27 requires an iPhone 11 or later, or an iPhone SE (2nd generation) or later, running iOS 27, which ships the same day.
| Key fact | Detail |
|---|---|
| Release | Monday, September 14, 2026, free |
| Supported watches | SE 3, Series 9, 10, 11, 12, Ultra 2, 3, 4 |
| iPhone needed | iPhone 11 or later, or iPhone SE (2nd generation) or later, on iOS 27 |
| Siri AI | Beta, English to start, not initially available in the EU on watchOS |
| New hardware | Series 12 from $399 and Ultra 4 from $799, in stores Friday, September 18 |
The eight Apple Watch models on Apple’s list
Apple’s watchOS page names Apple Watch SE 3, Apple Watch Series 9, Series 10, Series 11 and Series 12, and Apple Watch Ultra 2, Ultra 3 and Ultra 4. Six of those eight are watches people already own.
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The other two are new. Apple Watch Series 12 starts at $399 and Apple Watch Ultra 4 starts at $799, both reaching stores on Friday, September 18, with watchOS 27 preinstalled.
The models Apple leaves off
Apple Watch Series 6, Series 7, Series 8, Apple Watch SE (2nd generation) and the original Apple Watch Ultra do not appear on Apple’s compatibility list. Apple has not published an explanation, and it has not published a list of which watchOS 27 features those watches will continue to receive through older software.
Apple Watch SE 3, the $249 model that briefly went unavailable just before the event, is on the list.
Every watchOS 27 feature Apple has confirmed
Apple’s watchOS page and its September 9 press releases list the following:
- Siri AI with personal context, in beta and in English to start
- A dynamic app grid that surfaces frequently and recently used apps, with the Siri app featured
- A single-handed tap gesture that selects Smart Stack widgets with the index finger and thumb
- Smart Stack widget suggestions, including birthdays, a parked car and transit cards
- A Siri Modular watch face
- Workout Buddy with pace, distance and duration insights, working without a nearby iPhone, and available in Spanish
- Improved distance accuracy for treadmill and indoor walk workouts
- Cycle Tracking with perimenopause and menopause notifications and educational resources
- A streamlined, map-centered Find My app that combines Devices, People and Items
- Call Context, which surfaces relevant information during calls to a business
- Faster playback startup in Music
- Step counts that sync with the Health app
- Custom QR and barcode passes in Wallet for memberships and cards
- Child accounts with built-in protections, and Apple Watch For Your Kids setup without an iPhone
- The updated Liquid Glass display design
Where each headline feature actually runs
Being on the compatibility list does not mean every feature arrives. Apple draws three separate lines, and the strictest one involves the iPhone rather than the watch.
| Feature | What Apple says it requires |
|---|---|
| App grid, tap gesture, Smart Stack, Workout Buddy, Find My, Wallet, Liquid Glass | Any Apple Watch on the compatibility list |
| Siri AI on the watch | Series 9 or later, Ultra 2 or later or SE 3, paired with an Apple Intelligence iPhone, set to English |
| Sound Recognition and Music Recognition with Shazam | Series 12 or Ultra 4, with an iPhone 11 or later |
| Live Rewind and Siri Recap | Series 12 or Ultra 4, with an iPhone 16 or newer, in beta later in 2026 |
| Heart rate every 5 seconds and HRV every 5 minutes | The Health Sensing System hardware in Series 12 and Ultra 4 |
Siri AI carries two further limits Apple states plainly: it is not available to users under 13, and it will not be available initially in the EU on iOS, iPadOS or watchOS. Apple adds that it is working to find a path forward.
What Apple has not said
Apple has not published a release time for Monday, and it has not yet published an About watchOS 27 Updates support document of the kind that exists for watchOS 26. It has also not broken down, feature by feature, which of the new health tools reach a Series 9 or Series 10 rather than only the newest watches.
watchOS 27 lands on Monday, September 14. Series 12 and Ultra 4 follow on Friday, September 18, and pre-orders for both remain open now.
