The programme starts with a game against the Springboks on the same day as the United Rugby Championship final.
South Africa have two teams, Bulls and Stormers, in the play-offs alongside Welsh side Ospreys.
Players from both Wales and Springboks will be missing because the match falls outside World Rugby’s international window.
“I’m excited by the challenge of meeting the world champions Springboks in terms of creating some confidence and self-belief in this group of players,” said Gatland.
“South Africa will be missing a few players as well, but whatever team they put out we know they won’t be small. They’ll be big and physical.”
The four games in the summer programme will take Wales’ season tally to 18 internationals but Gatland wants to expose his players to Test match rugby.
“I was trying to get as many games as we possibly could this summer,” said Gatland.
“At one stage we were looking at playing Samoa, and I would have jumped at that, because this group of young players need as many games as they can possibly get to gain that experience.
“It is a lot of work for the coaching staff and we realised the challenge we’ve got, but it is our job to work them hard and make them better.
“They have to learn about the pressures of playing international rugby, how hard it is and what it takes to succeed.
“We are conscious there are a few holes in terms of depth in certain positions and we’ve got to increase the depth and competition for places.”
