watchOS 5.3.10 (build 16U711) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2026-03-24T18:34:23Z. The update package is 61.89 MB. This is a delta (partial) update that requires 5.3.2 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: ef12f16e6acae5b7b17e883692c3a18c7523a45d.zip.