Notes missing after upgrade to iOS 10 I just upgraded my iPhone 6 to IOS 10 and half of my notes are missing. I have a few notes under the cloud, gmail, and my phone but nothing is showing up under my email (not sure if notes were ever there).

Seems any note created or edited in the past 12 months are gone. I have already restarted the phone.
If you didn't backup the notes with iTunes or iCloud, then they are gonna permanently. On iPhone, there are two different kinds of notes: one is synced with iCloud and the other is local notes. I am aware of this after switching to a new iPhone. I guess the missing notes were stored locally.