The Sims 4 will release before the end of September, most likely during the last week of the month according to comments made by EA.
EA stated last night that The Sims 4 was on track to launch in autumn, but also highlighted it as a fiscal Q2 release. EA's Q2 ends September 30, with September 23 being the first day of autumn.
With that in mind, the most likely UK release date for the title is Friday, September 26.
Other titles due out from EA before the end of September include FIFA 15 and NHL 15.
The Sims 4 had initially been expected in spring but was pushed back for undisclosed reasons. Expect much more on the title at E3 next month.