Question: When do most schools go back after summer?
Disambiguated questions and answers: question: When do most schools go back after summer in the Northern Hemisphere?
When do most schools go back after summer in the Southern Hemisphere?
In the United States during the 20th century, when do most schools go back after summer?
In the United States during the 21st century, when do most schools go back after summer?
answer: August or September
January or February
shortly after Labor Day
earlier in August or even late July
Natural Questions answer: between mid-August and early September (from the Wikipedia article "Summer vacation")