Apple has said iOS 6, its next generation version of the mobile operating system, is releasing this fall. Apple typically launches a new version of the OS alongside a new device and rumors of a September 21 release for the iPhone 5 suggest the same for the OS.

iMore broke the news of the September 21 release, with an Apple event planned 9 days earlier - September 12. iMore said that Apple should have a final version of the OS to demo. A release around September 19 could happen, "if Apple sticks to previous release patterns." iMore's probably referring to iOS 4's and iOS 5's launch that took place 3 and 2 days before the release of iPhone 4 and 5, respectively.

Of course the release of iOS 6 is tied to the release of the iPhone 5. A September 12 unveiling for the phone is earlier than the iPhone 4S unveiling (October 4, 2011) and later than previous versions of the iPhone. Apple launched the iPhone 4 on Verizon during January 2011, so it's possible that the release of the 4S got pushed back to focus on the carrier. The iPhone 4 launched June 24, 2010.

iMore's sources also said an iPad Mini, seemingly the final name for a smaller version of the iPad, will be unveiled on September 12. There's no specific release date yet, though, but it will probably run iOS 6 from launch.

The information is supported by Jim Dalrymple of The Loop. "Yep," he said, to iMore's report. AllThingsD also heard from its sources an event is being planned for the week of September 9, with Wednesday (September 12) the date.

According to analysts, Apple's prepayments for inventory components also rose by $1.15 billion in Q2 2012. "In our view, an increase in inventory component prepayment may suggest that Apple is securing supply for potential new product launches," analyst Maynard Um said to clients July 30.

The Verge's sources have also corroborated the date, so it seems to be certain. It shouldn't really be a surprise considering that Apple, traditionally (barring the 4S), launches iPhones during June.

iOS 6, previewed at WWDC in June, is expected among a section of fans to feature a revamped iPhone UI. Apple didn't demonstrate a revamp at WWDC, but it didn't even show the iPhone 5; so, it may be holding back features.