watchOS 5.3.10 (build 16U711) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2026-03-24T18:37:11Z. The update package is 80.6 MB. This is a delta (partial) update that requires 5.3.8 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: e1329fb70a0ce4d6134d37a61768ef92c8636ad8.zip.