I was flying CLE-ATL yesterday, due to arrive at 5:30. We were on-time, despite leaving 30 minutes late when the copilot told us ATL had been briefly closed due to windshear, and we were being diverted (I'm thinking c'mon BHM!). Instead we circled for 30 minutes and landed at ATL. I had a 3 hour CRC visit and saw a number of flights delayed on the boards, including mine. Over 3 hours, some miraculously recovered (mine did), some did not. It did not look like it was all that widespread and ATL couldn't have been closed long. I also saw a couple flights close early and shut their doors on late connecting pax.