watchOS 3.1.3 (build 14S959) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2017-01-09T17:56:35Z. The update package is 132.08 MB. This is a delta (partial) update that requires 3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e0af5b7fa78e5c2fd925894d471ed778f8a32647.zip.