The "Batman v Superman: Dawn of Justice" star, 42, landed in Atlanta on July 7 and headed straight to Garner's temporary pad's guest house, reported Us magazine.
Garner, 43, is currently filming "Miracles From Heaven" in
Atlanta, while Affleck took on father duty and dropped off the kids at the Lovett School, where they're participating in a summer program.
The Argo star returned to Los Angeles early from their family trip to the Bahamas to "cool off for a few days" and for a work meeting before reuniting with his clan in Atlanta.