Apple has released the watchOS 3.1.3 software update for all Apple Watch users. The release notes confirm that the update is focused on bug fixes and performance improvements as suggested by the version number.
watchOS 3.1.1 was the previous public version of the Apple Watch operating system, although the update was temporarily pulled after issues with bricking certain hardware. watchOS 3.1.3 is the current version, and a watchOS 3.1.2 update was not released.
watchOS 3.1 was a bigger update that improved battery life after the major watchOS 3 release.
Today’s update is available through the Watch app under General → Software Update. Developers on the watchOS 3.1.3 beta (build 14S959) will see an update available as the released build today is 14S960.
Source : https://9to5mac.com/