Stranger Things season 3 was released on July 4, 2019. That means it's about time to get a more general idea as to when season 4 comes out. Netflix has been pretty quiet on when it's coming out, but they recently teased something on the Stranger Things Twitter account.
I'll happily read into this and believe this means we're getting an announcement of some sort, specifically a release date. There was also a teaser on the Stranger Things Instagram, which was saved on r/strangerthings.🕰️🙃— Stranger Things (@Stranger_Things) September 29, 2019
We're likely going to get an announcement in the coming days. I would expect a release date in late summer 2020. We'll update the article with specifics once they come out.
UPDATE
The announcement was in fact to confirm what we all knew, that Stranger Things is returning for a fourth season. Along with a press release talking about how excited Netflix is to work with the Duffer brothers.we're not in hawkins anymore pic.twitter.com/Y4hayuPKvu— Stranger Things (@Stranger_Things) September 30, 2019
“The Duffer Brothers have captivated viewers around the world with Stranger Things and we’re thrilled to expand our relationship with them to bring their vivid imaginations to other film and series projects our members will love. We can’t wait to see what The Duffer Brothers have in store when they step outside the world of The Upside Down.”
Ted Sarandos Netflix CCO | Source