Summer is a time when many academics do not teach. For some of us, particularly adjuncts, that is a time of financial hardship. But even for adjuncts without paid instructional work, and certainly for those in full-time positions, no teaching does not mean we have the summers off.
Academic work is judged on teaching, publications, and service or publications, teaching, and service–depending on the type of institution for which you work. Either way publications are an important part of the equation. Even community colleges, given a surfeit of applications, use publications to determine who to interview and hire.
Since teaching is a (sometimes more than) full-time job, work on publications is often shifted to the summer and Christmas break. We research and teach during the school year and write and submit over the summer. Or we revise and resubmit over the summer.
This summer, I have two book chapters, an article R&R, and a book to finish.
I also have to prepare my tenure and promotion portfolio.
No teaching does not mean I have summers off.