watchOS 3.1 (build 14S452) is an official Apple over-the-air update for the Apple Watch Series 1 (38mm), released on 2016-09-21T17:00:48Z. The update package is 946.24 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: 4b85e35f6616230860bb31e4d0478cf4e01518d3.zip.