Based on 2015 records, the 49ers and the Falcons will play the toughest schedule in the NFL next season.
Records alone don't determine a schedule's difficulty, of course, and the slate could line up nicely for the Falcons with a balance of home and away games and the like. It's unlikely to, however, considering the Falcons will be playing a lot of games on the West Coast, and the quality of their opponents on paper is significantly higher than it was this past season. Of course, if you expect some regression from the Panthers and even Broncos, the schedule will be a little more forgiving, but Atlanta's going to have to get a hell of a lot better to hang with them, even so.
As a reminder, here's all of Atlanta's opponents:
Carolina, New Orleans, Tampa Bay, Arizona, San Francisco, Kansas City, San Diego, Green Bay
Carolina, New Orleans, Tampa Bay, Los Angeles, Seattle, Denver, Oakland, Philadelphia
It's one of the major reasons I believe the Falcons won't take a major step forward in terms of record this season, if they take a step forward at all. Pray they surprise me.