Stranger Things unofficially has a Season 3. The Creators of the show, the Duffer Brothers have confirmed that they are in season 3 talks and that it should be announced by Netflix fairly shortly if not, at the end of season 2. Season 2 airs 10/27. Just in time for Halloween.
What is also interesting is that the brothers have an end in sight for the series already. They say, they would like it to last four seasons on Netflix and then be done as it’ll be hard to justify bad things happening to the kids every year.