that the Steam Summer Sale start date has leaked "as per tradition,"
reveals this to be
June 25th, right after the actual start of summer. They say this is also
"confirmed by multiple sources" (thanks
🕶 Steam Summer Sale 2019 date leaked as per tradition, it will
begin on June 25, 2019 at 10AM PST and will last for two weeks.
via SteamCN and confirmed by multiple sources.