watchOS 5.3.6 (build 16U662) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2020-03-24T17:21:17Z. The update package is 69.92 MB. This is a delta (partial) update that requires 5.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 6e42c4f5a215c727440e42a5f9cd720cc84a0693.zip.