Today Apple has released iOS 13.6.1 and iPadOS 13.6.1 to all supported devices. As the small increment in versioning implies, this build is all about fixing issues, and doesn’t bring any new features to the table.
iOS 13.6.1 addresses an issue that could cause unneeded system data files to not be automatically deleted when storage is low, and it addresses a thermal management issue that caused some iPhone displays to exhibit a green tint. It also has a fix for a bug that could cause Exposure Notifications to be disabled for some users.
iOS 13.6.1 is likely to be one of the last updates to the iOS 13 operating system as Apple has transitioned to working on iOS 14, an update that is set to be released this fall.
The iOS 13.6.1 update is a 110MB download, and should be ready for install right away if you check for it through Settings > General > Software Update. You may have already been notified about it.