It is speculated now that Nvidia is to launch the mid-range series 960 of GeForce graphics cards somewhere mid-October according to the typically well informed tage Akihabara. The GeForce GTX 970 and 980 however would be available directly or shortly after launch, but yes that GeForce GTX 960 would be a month away.
Nvidia is expeted to release the GeForce GTX 970 and 980 this week during their Game24 event.