watchOS 3.1.3 (build 14S959) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2017-01-09T17:56:27Z. The update package is 583.05 MB. This is a delta (partial) update that requires 2.2.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a4f0f95f417145a57e51cf61756a73264335ce6e.zip.