watchOS 5.3.9 (build 16U693) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2021-01-26T18:26:31Z. The update package is 502.34 MB. This is a delta (partial) update that requires 5.0.1 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 7c130eeb91241fe8d1f5f5ee68af9eacd3aa49e8.zip.