watchOS 3.1 (build 14S452) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2016-09-21T17:00:49Z. The update package is 947.04 MB. This is a full OTA update that can be applied from any compatible base version. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 85df20becf06382dd8e24d80213d211a289c84c8.zip.