The Midsummer Fire Festival will run from Friday, June 21 to Friday, July 5 this year. As always, check your ingame calendar to determine the exact start and stop times for your server. While there aren't actually a lot of achievements associated with the Festival (the meta consists of only six), three of them require serious travel time, and one also requires a set of dangerous trips to enemy capitals. For the trouble, Alliance players are awarded the Flame Warden title, and Horde players Flame Keeper.
If you're starting from scratch, this is definitely one of the more work-intensive holidays necessary for the completion of What A Long, Strange Trip It's Been. However, even a fresh character can afford to get all the rewards from holiday vendors if you're diligent about hitting all the holiday's fires, quests, and dailies.
The basics of the holiday involve "honoring" or "desecrating" a series of fires across Azeroth and Outland. For convenience, we've listed all of the fires on each continent in a specific direction so you can reach them as efficiently as possible. This year, Blizzard has updated the holiday boss' loot list with ilevel 480 cloaks and weapons and added a set of fires to Pandaria, but there aren't that many; you'll only have an additional 7 fires to honor and one to desecrate on the continent.