watchOS 5.3 (build 16U569) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2019-07-22T19:15:20Z. The update package is 201.71 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: 83c36d0ec7f59a438ca27af1127900a3c970d61a.zip.