watchOS 5.3 (build 16U5545c) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2019-06-11T17:13:46Z. The update package is 153.77 MB. This is a delta (partial) update that requires 5.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 202d4c3f243d3ff32d82b84c622d0385e8ebfd76.zip.