watchOS 5.3.10 (build 16U711) is an official Apple over-the-air update for the Apple Watch Series 4 (40mm), released on 2026-03-24T18:36:21Z. The update package is 65.04 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: 6661a651c8dcd4e9af89c5ec701d8b78ec612934.zip.