Visa Wait Times
This is a useful website for foreign students, including those who might be going home for the summer. It says the average wait time for an interview for Student/Exchange visitors visas in Beijing, for example is 22 days.
In New Delhi, it’s only 7 days for Student/Exchange visas, but 112 days (!) for Visitors. Plan ahead, I guess, if you want to tour the U.S.A.