There are some retirement expenses that everyone has -- things like housing, insurance, groceries, and healthcare. Other retirement expenses are specific to the individual, like travel or big-ticket purchases. And then there are some retirement expenses that seem to depend upon where you live.

A recent study by American Advisors Group (AAG), a top reverse-mortgage lender, looked at retirement trends by region. It highlighted some interesting expenses that people living in each region were more likely to incur than those in other areas of the country. Here are the top unique retirement expenses by region.

Senior couple on sailboat looking out at ocean

Thinking of retiring in the South? A boat might be in your future. Image source: Getty Images.

Northeast: Living in a retirement community

Retirement communities aren't just for elderly adults who can no longer care for themselves. Independent retirement communities give retirees the opportunity to live on their own without having to bother with maintenance, property taxes, or any of the other expenses that come with being a homeowner, and it may also give them a chance to meet new friends.

Residents of Northeast states -- including Connecticut, Delaware, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont -- were more likely to choose this lifestyle compared with residents in other regions.

The cost of living in a retirement community depends on where it's located, which community you choose, and what amenities it offers. Monthly costs can range from $1,500 on the low end to as much as $10,000 on the high end. If you'd like to spend your later years in a retirement community, try to estimate how much you can reasonably afford each month. Or choose a community you like and ask about its costs so you know how much you need to save in order to enjoy your retirement there.

South: Buying a boat

Residents of states in the study's Southern region -- including Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, and West Virginia -- were more likely to purchase a boat in retirement, according to AAG. This isn't all that surprising when you consider that all but five of these states rest on the ocean or the Gulf of Mexico.

The study didn't specify the type of boat Southern retirees were more likely to buy. If you're someone who wants a boat in your future, estimate the costs of the boat you'd like before you retire. You'll also have to factor in the cost of storage, fuel, a trailer, and winterizing the boat, if necessary. Your state will likely require your boat be insured and registered as well. Build these costs into your retirement plan now; you don't want your pastime draining crucial funds set aside to cover your basic living expenses.

Midwest: Owning a pet

Midwesterners were the most likely to own a pet in retirement, according to the AAG study. This includes residents of Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. The study didn't drill down into which types of pets, but dogs and cats are generally the most common.

A few studies have looked at the average cost of ownership over a pet's lifetime and found that for dogs, it's usually about $15,000 to $18,000. Cats are slightly less expensive but can easily cost between $8,000 and $15,000, depending on whether you pay for things like pet insurance. These estimates don't include the cost of unforeseen vet bills, and if you have multiple pets in the home, you can expect these costs will be higher. If you'd like a companion in retirement, factor these expenses into your plan and consider buying a pet insurance policy so an injury or illness doesn't cost you a hefty chunk of your savings.

West: Continuing education

Residents of Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming appear to have the greatest ambitions for their retirement, according to the AAG survey. Not only were they the most likely to want to continue their education in retirement, they were also the most likely to plan to work a part-time job. That could be a welcome source of income for those spending money on furthering their education.

Spending a lot isn't always necessary, though, unless you hope to get a degree. There are a number of free resources online, including courses from top universities -- good places to begin if you're just trying to satisfy a curiosity. You might also be able to audit courses at a university near you if you prefer attending classes in person.

If you do intend to get a degree or pay for classes in retirement, price this out now and factor in inflation, which continues to drive up the cost of tuition.

You may not have any of these expenses in retirement, but if you think you will, it's a good idea to start planning now. If you don't budget for them, it could jeopardize your financial security in your final years.