watchOS 5.0 (build 16R364) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2018-09-12T19:18:54Z. The update package is 785.61 MB. This is a delta (partial) update that requires 4.2.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 115cf9b039384a6dabb1c5ae2457d27cee0d2a54.zip.