When I was a newlywed, my mother-in-law and I were talking cooking and she confessed that she rarely used her slow cooker in winter, when you're craving the kind of stews and braised that taste so good in colder months. Instead, hers saw heavy use in summer.
When you think about it, that makes all kinds of sense. During summer you're spending time outside and having fun...she was an avid gardener and would have much rather spent time there than the kitchen. And you don't need to abandon your healthy diet, either.
As it turns out, you can make all kinds of summery dishes; pulled chicken (instead of pork) comes immediately to mind, but you can go vegetarian with eggplant and chickpea stew, Mexican with pork carnitas, or Indian(ish) with curried vegetables. These dishes make use of the abundant fresh produce that the season offers and allows you to be out there enjoying the weather instead of inside stirring a hot pan on the stove.
My family is actually more on the go during summer than we are during the school year; we're running around to library programs, play rehearsals, and community events. So having dinner ready to go when we are, with all the work handled before the day gets crazy, is a bonus.
Do you use your slow cooker in summer?