watchOS 5.3.10 (build 16U711) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2026-03-24T18:34:10Z. The update package is 493.89 MB. This is a delta (partial) update that requires 5.0 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 5ec10e6e12d37ac53357669f800f98286446fb1f.zip.