Here is a list that my son got from the Jack Kent Cooke Foundation of some summer programs in STEM fields:
Science, Technology, Engineering, and Math (STEM)
Boston University Research Internship in Science and Engineering (RISE): Boston, MA
Brown University SPARK Science Program for Middle School Students: Providence, RI
Canada/USA Mathcamp: University of Puget Sound in Tacoma, WA
Clemson Summer Scholars: Clemson, SC
Engineering Innovations: Johns Hopkins in Baltimore, MD
Environmental Studies Summer Youth Institute: Hobart and William Smith Colleges in Geneva, NY
Google’s Computer Science Summer Institute: Mountain View, CA (for graduating seniors only)
iD Tech Camp: Various college campus locations nationwide
MIT’s Minority Introduction To Engineering and Science (MITES) Program: Cambridge, MA (for rising high school seniors only)
MIT Selective Summer Programs: Cambridge, MA
Stanford University Mathematics Camp: Palo Alto, CA
Stanford University Medical Youth Science Program: Palo Alto, CA
Stanford Office of Science Outreach Internships and Programs: Palo Alto, CA
Summer Science Program: Socorro, NM (New Mexico Institute of Technology) and Santa Barbara, CA (Westmont College)
UC Santa Barbara Research Mentorship Program: Santa Barbara, CA
UConn Mentor Connection: Storrs, CT
University of Michigan Math and Science Scholars: Ann Arbor, MI
University of Pennsylvania Summer Academy in Applied Science and Technology (SAAST): Philadelphia, PA
University of Pittsburgh Cancer Institute Summer Academy (UPCI): Pittsburgh, PA
University of Rochester Summer Pre-College Programs: Rochester, NY
Hope this helps