watchOS 3.1.3 (build 14S960) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2017-01-23T18:02:37Z. The update package is 21.37 MB. This is a delta (partial) update that requires 3.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 7ea135100f0a504a75d8f69b703c109167f75fb6.zip.