No, in the summertime, after the sun goes down, the air conditioners run much less.
Not up in my neck of the woods or any where that is high humidity.
Most of the brownouts and blackouts occur at night in the Northeast in the middle of summer.
People up here turn their air conditioners off when the go to work during the day and then turn them on when they get home at night.
When we are in a heat wave all of the warnings to reduce power consumption take place at night.
Maybe in Michigan, down here in Tucson not really. Even our “cool” summer nights are higher than most people have their thermostats set, and people with swamp coolers turn them on sometime in May and pretty much leave them on until mid-September.