watchOS 5.0 (build 16R364) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2018-09-12T19:19:22Z. The update package is 738.93 MB. This is a delta (partial) update that requires 4.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5c5d912ef7af1d242df786870beb79fbc5f9a58f.zip.