I have a feeling many of you, as I, will soon be needing this guide from Bradley Chambers:
According to this Apple support document, Apple Watch triggers a current backup when you unpair it from your iPhone. The iPhone has to be in range in order for the backup to take place, though. I didn’t read this before I started the process, so I simply kept Apple Watch paired to the old phone, but then tried to pair to the new iPhone. When I launched the Watch app on the new iPhone, I was told that I needed to wipe my existing Apple Watch. You can do this by going to Settings → General on Apple Watch. When you back up your iPhone to iCloud and/or iTunes, your backup includes your Apple Watch data.
This is a little confusing to me. From what I can gather, a current backup of your Apple Watch exists on your iPhone only when you un-pair the two within range, and the backup of your iPhone in iCloud or iTunes will have a copy of this Watch backup. The Apple support document says much the same:
When you unpair your Apple Watch from your iPhone, your iPhone automatically creates a backup of your Apple Watch. Unpairing will erase all data from your Apple Watch. If your Apple Watch is unpaired while out of range of your iPhone, the backup won’t be created.
I have a feeling that I’ll be trading in my 5S for a 6S shortly, which means that I will first have to un-pair my Apple Watch within range, then create a new, full backup of my 5S. Only then should I take my current phone in to my local Apple Store for the upgrade credit. I should then take my new iPhone home, set it up from the 5S backup, and then re-pair my Watch, thereby restoring its connection to my new phone.
I’m still a little unclear as to how Chambers was able to swap his iPhone and have a backup of his Watch data without doing the un-pair/re-pair dance. It sounds like his iPhone backup happened to have a recent Watch backup, too, but I’m not sure how that’s the case if he didn’t un-pair it. I have asked him, and will update if I hear back.
Update: Chambers has no idea either how he had a recent Apple Watch backup. I’m not gambling on that stroke of luck; I intend on following the steps above.