Apple has released two updates as iOS 18.6.1 for iPhone along with watchOS 11.6.1 for Apple Watch, and the combination of the two system software updates returns the blood oxygen monitoring feature back to Apple Watch. Previously, Apple had to remove the blood oxygen monitoring feature from Apple Watch Series 9, 10, and the latest Ultra 2 models, because of an ongoing legal dispute with another tech company.
No other features or security patches are included in these releases, but if you’re an Apple Watch Series 9, 10, or Ultra 2 owner (or shopper, Apple Watch 10 is $100 off from Amazon) this is certainly a series of updates you’ll want to get so that you can get the blood oxygen feature back on your device.
How to Download & Install iOS 18.6.1 Update
Always backup iPhone to iCloud before starting a system software update.
- Open the “Settings” app on iPhone
- Go to “General” and then go to “Software Update”
- Choose “Update Now” to download and install iOS 18.6.1
The iOS 18.6.1 update is pretty small and should install quickly on your iPhone, though it still requires a reboot.
How to Download & Install watchOS 11.6.1 Update
To get Blood Oxygen monitoring back on your Apple Watch you also need to update your wrist device:
- Open the “Watch” app on iPhone
- Go to “General” and then go to “Software Update”
- Choose “Update Now” to download and install watchOS 11.6.1
Advanced users can choose to update an iPhone by connecting their device to a computer and using IPSW firmware files, though this is unnecessarily complicated for most users who should simply use the Software Update mechanisms on their iPhone.
iOS 18.6.1 IPSW Firmware Download Links
If you’d like to update iOS manually with IPSW files, the followin links point to Apple CDN:
iOS 18.6.1 Release Notes
Release notes for iOS 18.6.1 mention the Blood Oxygen measurement feature and nothing else:
This update provides a new Blood Oxygen experience for users in the United States with Apple Watch Series 9 and Series 10, and Apple Watch Ultra 2. Measurements are calculated on iPhone and viewed in the Health app.
For information on the security content of Apple software updates, please visit:
https://support.apple.com/100100
Apple Watch Blood Oxygen Update Press Release
Related, Apple issued a press release for the updates to discuss the Blood Oxygen monitoring feature:
Apple will introduce a redesigned Blood Oxygen feature for some Apple Watch Series 9, Series 10, and Apple Watch Ultra 2 users through an iPhone and Apple Watch software update coming later today.
Users with these models in the U.S. who currently do not have the Blood Oxygen feature will have access to the redesigned Blood Oxygen feature by updating their paired iPhone to iOS 18.6.1 and their Apple Watch to watchOS 11.6.1. Following this update, sensor data from the Blood Oxygen app on Apple Watch will be measured and calculated on the paired iPhone, and results can be viewed in the Respiratory section of the Health app. This update was enabled by a recent U.S. Customs ruling.
There will be no impact to Apple Watch units previously purchased that include the original Blood Oxygen feature, nor to Apple Watch units purchased outside of the U.S.
You’ll want to update your Apple Watch as well as your iPhone to regain this functionality on your devices.
If you’ve been thinking about getting an Apple Watch but held off due to the removal of the Blood Oxygen feature, now’s a great time to snag one as the feature returns, because Apple Watch Series 10 starts at $299 on Amazon, which is $100 off the retail price from Apple.