watchOS 6.3.1 (build 17U224) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2026-02-02T18:44:27Z. The update package is 272.61 MB. This is a delta (partial) update that requires 6.2.6 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: c9f5aa903716139cd5bbe942c133d8a221a8b12b.zip.