I'm in NY, so like many here, it's Sept after Labor Day through late June. It's fine, it's what we're used to, and makes sense to have off for the hottest part of the summer, July and August. Most schools in the area don't have air-conditioned classrooms. And lots of families here traditionally take vacation during the last week or two of August.
The kids gets lots of time off throughout the year, including at least a week (often more) for Christmas and Spring breaks, plus "Winter recess" in Feb, the week of President's Day (which started in the 70's during the energy crisis to save on heating.)
We also get numerous holidays including some that other regions may not have, like Columbus Day, Veterans Day, Election Day, and MLK Day. Plus, because we have a large Jewish population, we often get 2 or 3 more days for religious holidays in the fall, if they fall on weekdays. And because Spring break is scheduled to coincide with both Easter and Passover, it changes every year and is often longer or sometimes broken into 2 separate shorter breaks. Last year, NYC public schools also added a couple of Muslim holidays.