watchOS 3.1.3 (build 14S959) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2017-01-09T17:56:24Z. The update package is 605.57 MB. This is a delta (partial) update that requires 2.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9bcb412b71eda94175bd950293b8663f30ffd202.zip.