Are you allowed to take summer classes as a Transfer Student the summer before Fall?

I am a sophomore trying to apply to transfer for Fall 2018 but I was wondering if I get accepted, can I take summer classes at my new university the summer before Fall semester?
It is kind of essential that I am able to take summer classes in order to graduate on time because I don’t want to throw money away for an extra year (both my current school and schools I want to transfer to are NOT cheap). At my current college, I would be able to graduate on time by taking summer courses this summer and the following. So now I am contemplating staying at my current university just to be able to graduate on time even though I have wanted to transfer ever since coming to this college. What do you think???

If graduating on time is more important than whatever reasons you have for transferring, then you obviously shouldn’t transfer.

Summer classes prior to the fall semester are usually unavailable for transfer students. Though, I know of some schools that offer “summer transfer programs” for STEM majors and whatnot. See if you can find any programs that could apply to you.

This is a question that you need to ask the place that you are applying to.