1. Do you have bookings? If you have regular gigs in the summer then of course you will keep rehearsing. If you are a paid choir and expected to do your regular church services or other concerts there is not discussion. Even with paid professionals, the following ideas need considering.
Depending on where you live, you have holiday times to deal with. In England, August is holiday time and many people are away. In France, they have a time in June and again in August when people take time off and travel. In Canada, it is usually mid-July to mid-August. It makes it hard to get an audience and to get a balanced choir.
Some choirs have definite summer activities and actually have a different group of singers participating. A group in Florida does Christmas music that is taped in the summer for a special presentation. They have singers who participate just for that. Another travels to various venues to uplift others during the summer. These are summer choirs. Cool idea or perhaps a hot time in the old town - oh dear!
2. Does your choir want to sing? We have many busy people who as in #1 above want to travel or just hang out during the summer. Typically, clubs and other activities have time off in the summer. Children are home from school usually for just under 2 months in Canada, longer in the U.S. and shorter but more often in some European countries. If your choir is in time off mode, then it may be wise not to try to rehearse but take the time away to rejuvenate. Together you can decide what is best.
3. Do you have a comfortable place to practise? If you don't have air conditioning perhaps you have a spot with a cool basement or very thick walls. You may even live in a place that doesn't see overly warm summer temperatures. Here we find the humidity plays havoc with voices, instruments and tempers. It is a big issue in my part of the world.
I like the change. I come back to choir with a fresh perspective, and more energy. If I keep going and there is never a break, I find myself getting stale. That is not to say I do nothing musical, but it is different. My mum used to say, "A change is a good as a rest." Truer words were never spoken.