iPadOS 9.3.1 (build 13E238) is an official Apple over-the-air update for the iPad mini 3 (Cellular), released on 2016-03-31T16:53:45Z. The update package is 288.17 MB. This is a delta (partial) update that requires 9.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: afc8adb58c9efd71b2c29ba3a8f7b1e1f38eec00.zip.