https://www.gamespot.com/articles/overwatch-summer-games-return-for-a-third-season/1100-6460935/

Blizzard Entertainment has announced that Summer Games is returning to Overwatch again this year. The annual summer event will return August 9 and continue to August 30.

Summer Games first came to Overwatch in 2016 in celebration of the Olympics. The event unlocks content drops of exclusive summer-themed hero skins, as well as Lucioball--a Rocket League-type game mode. Lucioball returns for Summer Games 2018, and promo images seem to suggest the mode's arenas are moving to Busan, South Korea.