Blizzard has posted notification on the official site that Diablo 3's Season 6 will be ending on July 22nd in all regions. After a two week break, Season 7 will begin on August 5th.
At this point no details on Season 7 rewards have been posted but will be in the coming weeks.
Note that all heroes, rewards, and progress will convert to the appropriate non-Seasonal game mode. Any items, gold, Paragon experience, achievements, Artisan levels or recipes, Stash space, and Blood Shards earned on Normal Seasonal heroes with transfer to your Normal non-Seasonal heroes when the season is over. Similarly, anything you’ve earned on Hardcore Seasonal heroes will transfer to your Hardcore non-Season heroes instead.
You can read more on the Diablo 3 community site.