We talked to some experts about what parents can do to ease the transition — plus, what to watch out for if there's a more serious problem.
Here's their list of tips:
Listen to your kid
Be available, says Lynn Bufka. If children have questions about school, or, once school starts, something exciting happens during the day, parents should make time to listen. Sharing the excitement can help ease concerns.
Tune into what your kids are talking about. "Emotionally, parents are the safe place for children to experience emotions and to help them develop the language around expressing emotions," says Bufka.
Beyond listening in general, drill down to the specifics. "It's important for parents to explore with their kids what they're feeling anxious about," says Bufka.
If parents know what, exactly, is making students nervous — friends, classes, a new teacher — they can help problem-solve.
Let kids be the experts
Eleanor Mackey, a psychologist with Children's National Health System in Washington, D.C., suggests asking kids what might make them feel better.
"Let them generate solutions," she says, "Ask them what helps them feel better in other scary situations."
If they need help coming up with ideas, parents can help them role-play tough situations or come up with strategies they can use in situations that make them worried.
Create a positive expectation. Talk about things your kids can look forward to in school, past experiences they've enjoyed. Friends or field trips are good examples.
Talk through previous triumphs
Many kids have been nervous or anxious before, so reminding them of their own successes with similar situations can help.
Try: "Remember last year, when you were feeling this way? You got through it."
Reassuring kids that they have the tools to get through the challenge ahead, because they've overcome their fears in the past, can go a long way, says Lynn Bufka.
Eleanor Mackey says parents may be unsure what to say in situations like this. She offers a template:
"I understand you are scared – that's just fine. I also know that you can manage this. Remember last year when you were so nervous but you did it and made it through and ... made a great new friend, did well in Spanish, etc..."
Reach out to the teacher
"I'm surprised at how reluctant parents are to talk to the teacher," says Mackey. "They don't want to be that parent, or they don't want to label their kid with issues."
And yet, she says, teachers have consistently told her they like hearing from parents.
Educators spend a lot of time trying to figure each kid out, she explains, so if you can save them the time, why not share? Parents are, after all, the experts on their kids.
Maybe your child is scared to answer questions in front of class, or has anxiety about being put on the spot — let the teacher know. She (or he) can use that information to help design the class, or maybe there can be more small-group work instead.
Parents can also tell their kids they've talked to the teacher, which can lower anxiety and send the message that the adults are on their side.
Start the routine early
"It's always helpful to practice your routines before things start," says Bufka.
Find (and clean!) backpacks, lunch boxes, folders and other supplies. Plan ahead and get the child involved in the planning process — have them get their belongs ready, etc.
"That gives the child a sense of mastery over the situation," Bufka explains. "Getting your child engaged about the new thing will help them feel like it's more under their control."
Often, families try and squeeze in a last fun adventure right at the end, but that can make things worse. Don't wait for the night before, says John Kelly, who is also the president of the National Association of School Psychologists. "You really need to start that adjustment early."
That means getting up earlier — and going to bed earlier too.
It's kind of a no-brainer that sleep is essential, Mackey points out, but patterns can't be adjusted (literally) overnight.
"Kids really get out of rhythm in the summer," she says, and this has a bigger impact than adults realize.
"When we're tired, we're moody, and little things can feel really big," Mackey explains. "Anxiety is much worse if sleep is bad. Make sure you have a good quiet routine and early enough bedtime that your child can get sufficient sleep."
Oh, and turn off that tablet or smartphone before bed, too.
Do a dry run
If it's a new school or a new neighborhood, introduce students to that situation before the big day. Visiting the school, or walking to and from the bus stop, can go a long way, says Mackey. You may have to do this more than once to make it seem familiar, she says. "Just once may lead to more anxiety."
A dry run can help even if it's not a new school. Kelly calls it: Say Hello To the School Again.
It's a great way to remind anxious kids they've been here before. Many schools are open the week before Day 1, often teachers are around too. If the school has an orientation, don't miss it.
When kids can make social connections before they start school, that's a really helpful step, says Kelly. Many kids have anxiety around friends, 'Who's going to be in my class? Who can I sit with at lunch? Ride the bus with?'
Especially for older students, comparing schedules with friends can help.
Don't ignore clothing anxiety
Parents may not think that what you wear on the first day matters, but for kids it can be huge. Especially, John Kelly says, in the middle and high school years.
Read some books
Kelly recommends School's First Day of School, by Adam Rex. It's about how nervous the school itself is. First Day Jitters by Julie Danneberg is helpful for kids starting new schools. And, Kelly says, for really young kids try Nancy Carlson's Look Out Kindergarten, Here I Come. Carlson's book also has a Spanish version: Preparate, kindergarten! Alla voy!
Chill out after school
Give kids a break after school, says Mackey. They don't need a lot of time, 5 to 10 minutes is just fine. Kids, she explains, need this after a hectic day when their brains are in overdrive.
Try doing it with them. A few minutes of quiet or light conversation can be great for the whole family — and it's another opportunity to connect with your kids.
Remember: Easing anxiety can take time
Not everyone is going to adjust to a new situation on the first day. Be patient. Each day can bring new challenges. This is especially true for older students, who are navigating new classes, different teachers and changing schedules.
It's very normal for kids to have trouble for a week or two weeks into the school year. "It's all new," says Kelly. "They're re-starting routines, or starting routines for the first time, and that can take a while."
Parents have anxiety, too
"It's important for parents to realize that schools are filled with professionals who work with children all the time," says Bufka. Remember, Kelly adds, kids are going to pick up cues from parents, so making sure you're comfortable too is an important piece.
Signs that it's not normal
There are some warning signs that your child may need some extra help. Kelly ticks off a few: If you really see your child struggling, having a really difficult time just getting to school or feeling increasingly anxious at night time.
Lynn Bufka says as a parent, you're in the best position to observe changes in their behavior.
"If the child is refusing to do things that they've normally done, or that they've not had difficulty doing before," she says, "that's a sign that something isn't going right."
Maybe it's a bully, or your child is really overwhelmed and they need some extra work with a psychologist.