The weather outside may still be sweltering, but summer is already coming to an end for some students in the U.S.

Depending on where you live, kids in your community may be starting school this week, while others have an entire month or more left before they need to hit the stores for new backpacks and pencils. In fact, research shows there is more than a month between some of the earliest and latest back-to-school start dates.

In the Southeast, for example, kids are headed back to school before July ends, while others in areas like the Northeast are still smack dab in the middle of summer.

By Thursday, July 25, all students in Lamar County, Mississippi were back in school. Atlanta Public Schools welcomes kids back on Aug. 1, marking the first wave of the school year. Students in Buffalo, New York, however, won't see the inside of a classroom until Sept. 1 or later while kids in the Chicago Public School district will start returning on August 26.

Here is what to know about back-to-school dates around the country.

More:Are schools asking too much for back-to-school shopping? Many parents say yes.

When do schools around the country go back? 

An analysis of more than 13,000 public school districts conducted in 2019 by the Pew Research Center found that in broad terms, schools in the South and Southwest tend to return to school earlier than those in the Northwest and along the East Coast.

Pew found that:

• By mid-August, nearly all public school students in the region covering Alabama, Kentucky, Mississippi and Tennessee were back in class.
• Not a single district, however, in the New England and Middle Atlantic states went back until late August.
• Some districts that operate on so-called modified year-round calendars begin in late July.
• Some students in New Jersey were not going back until the second week of September.

Why do summer breaks vary so much from coast to coast?

You may have heard the popular explanation that school schedules historically were based largely around agrarian culture. It is a common belief that education had to be tailored around the cycle of crop growth and harvest, meaning Southern children were needed on the farm during the most labor-intensive times of the season while Northern children were already living in a more industrialized setting that didn't require the same farm labor.

This theoretically meant Southern children left school earlier and went back earlier. In reality, however, it is more likely those children helping on the farm would be needed in the spring during planting and the fall during harvest, not the sweltering summer months.

This explanation may be rooted in some truth, but experts say it is more likely most school schedules were tailored around the needs of the community.

“Agrarian cycles are generally cited as the reason for summer breaks, which supposedly allowed for young people to assist with responsibilities on family farms,” Julie Gorlewski, Senior Associate Dean for Academic Affairs and Teacher Education at the University at Buffalo, previously told USA TODAY. “However, prior to efforts toward standardization in the late 19^th century, school calendars reflected the needs of their communities."

What factors go into choosing back-to-school dates? 

Other major considerations are weather (before the advent of A/C you did not want to be in a schoolhouse in the south in the peak of summer), local and national holidays, collective bargaining agreements, government funding and regulations.

For example, the New York State Department of Education places limitations on when schools can be in session. In New York, the school year can begin no earlier than September 1 and can extend no later than June 30. If public school districts want any state aid or funding, they have to adhere to these guidelines. The state also requires a minimum of 180 days of instruction per school year.

“In short, decisions around school calendars reflect the kind of tension between central and local governance that characterizes and sustains a democratic republic,” Gorlewski said. 

Parents and teachers weigh in

"My kids go back the day after Labor Day and I like starting in September because we get to enjoy the summer," said Julia Fuller, whose kids go to a public school in Jefferson County, New York. "I would love year-round with more breaks to alleviate the need for childcare for two straight months, though."

Emily Simril, a former teacher and mother of three children attending school in Greenville, South Carolina, said she prefers the later start dates that are common in southern states.

"As a parent and former teacher, I think the earlier start date works well," she said. "For all teachers and middle/high school students to be able to finish the second quarter/first semester prior to winter break is ideal."

"We're ready!" Andre Simmons, principal at the Albany Middle School also told USA TODAY. Students in his Dougherty County, Georgia school are headed back on July 31, which is slightly earlier than the usual August start date. However, he thinks the adjustment is overall better for the school's teachers and pupils.

"After the pandemic, we realized that we have got to space things out because we have an emotional, mental health crisis going on," he said. "So we need to give people more time, especially teachers."

And while you might expect all students to dread going back, Simmons said some of his pupils have told him they're ready. "I think they miss their friends and they're just ready to be back," Simmons said.