Riot Fest will return to Denver from September 2-4 this year, and to Chicago from September 16-18, but sadly there won't be one in Toronto. The fest writes on Facebook:
With recent local changes in Riot Fest’s partnership in Toronto, the planning process and resources required in staging a fest in Ontario was no longer compatible because of the available timeline. While Riot Fest has fallen in love with Toronto and the province of Ontario because of all of the great music fans who have welcomed and supported us in these last few years, Riot Fest 2016 will only take place in Denver and Chicago. We have every hope that we'll be back in Toronto in the near future, and, in the meantime, we'll begin announcing the lineups for Denver (Sept. 2-4) and Chicago (Sept. 16-18) shortly.
Bummer about Toronto, but stay tuned for the Denver/Chicago lineups.