Due to the rise in COVID cases, Los Angeles County officials expanded their mask mandate for indoor/outdoor 'mega events.'
According to SF GATE, 'mega events' are defined as indoor events with more than 5,000 attendees and outdoor events with more than 10,000. All those in attendance must wear a mask at all times, except when eating or drinking. The expanded mask mandate will go in to effect on Friday, August 20.
This will affect their larger stadiums, as well as future concerts, festivals, sports games, etc.
More information here.