watchOS 5.3.10 (build 16U711) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2026-03-24T18:34:49Z. The update package is 105.69 MB. This is a delta (partial) update that requires 5.3.6 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 74fcf38ccbc041c1dbb2267f693479f41872136a.zip.