watchOS 5.3.10 (build 16U711) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2026-03-24T18:34:53Z. The update package is 102.21 MB. This is a delta (partial) update that requires 5.3.9 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 50b7928145dee60d2abc4a5ed8cd966331b80ed5.zip.