Restore Apple Watch from a backup
Your Apple Watch content backs up automatically to your paired iPhone, and you can restore it from a stored backup. Apple Watch backups are included as part of your iPhone backups to iCloud or iTunes, but you can’t view information in the backups in iCloud.
Back up and restore Apple Watch
Back up your Apple Watch: When paired with an iPhone, Apple Watch content is backed up continuously to the iPhone. If you unpair the devices, a backup is performed first.
For more information, see the Apple Support article Back up your Apple Watch.
Restore your Apple Watch from a backup: If you pair your Apple Watch with the same iPhone again, or get a new Apple Watch, you can choose Restore from Backup and select a stored backup on your iPhone.