While the population of the United States continues to grow, some states are especially on the rise. According to the World Population Review, while the population increase in the U.S. between July 2017 and July 2018 was 0.6%, the growth in the two states with the highest growth was 2.1%. That adds up to a pretty massive leap in population.

Here are the 4 fastest-growing states in the U.S.

Arizona

Credit: Davel5957/ iStock

Why Arizona? You may think of Arizona as home to snowbirds and cacti. But there are many reasons why Arizona is the fourth fastest-growing state in the country. Today, Arizona has over 7 million residents. But just 40 years ago, there were less than 2 million people who called Arizona home. So why are so many people flocking? Arizona has lots of job opportunities right now, which is a significant driving factor, according to AZ Big Media. Another reason is the excellent public transportation in Phoenix, the largest city in the state. Often people who live in a city with poor public transit look for a place with better transportation options when they move. And although the weather can be scorching hot in the summer — think 120 degrees Fahrenheit — there is warm weather, sunshine, and low humidity all year.

Utah

Credit: anthony heflin/ Shutterstock

One thing bringing people to Utah, especially from California, is the lower cost of living and more affordable houses, according to California Movers. Also, schools are good in Utah, and residents generally feel safe. While there is some crime in Salt Lake City, the rest of the cities and towns can boast 80% less crime than the national average.

Aside from all of these number and stats, the landscape in Utah is beautiful. The Rocky Mountains cut through Utah, and the Great Salt Lake and the salt flats are fascinating sights to behold. Also, Utah has what many people consider to be a perfect climate. Utah has mild yet snowy winters so people can enjoy skiing and other winter sports in places like Park City. And the summers are warm, but not too hot or humid like other places around the country. And while not all of Utah is mountainous, nearly 80% of Utah residents live in Salt Lake City or the surrounding metropolitan areas, so most people are near the good stuff. It's Utah's growth rate of 1.64% that places it in third place on this list.

Idaho

Credit: Charles Knowles/ Shutterstock

Much of the migration to these four states comes from priced-out Californians. California is the most populous state in the nation. And yet with the cost of living beyond what many people can handle, more and more Californians are heading out and making new homes in places like Idaho. According to East Idaho News, the cost of living in Idaho is 7.8% lower than the national average. Not only that, Idaho has one of the lowest tax burdens in the nations — 29.6% below the national average. For a family coming from California or another pricey state, moving to Idaho means the chance to improve their quality of life quite a bit.

Much like Utah, the majority of Idahoans live in the urban area of Boise with much of the state still fairly remote and underpopulated. And believe it or not, a good chunk of Idaho is very much desert lands. But the parts that aren't are stunning, with vast mountain ranges and expansive wilderness. And for all of these reasons and more, Idaho's population rose 2.1% between July 2017 and July 2018. And the population over the last 30 years has nearly doubled, with an estimated 1,790,182 people living in Idaho currently.

Nevada

Credit: 4kodiak/ iStock

Nevada and Idaho tied for the largest percentage of growth at 2.1% growth from July 2017 to July 2018. But since Nevada has a larger population, with an estimated 3,087,025 people living there today, it claims the title of the state with the fastest growth.

What is causing people to move to the state of Nevada en masse? The biggies are low housing costs and lots of job opportunities, according to the Pahrump Valley Times. But another large chunk of people moving to Nevada, 29% to be exact, are making their way to the state for retirement. And who could blame them? Legal gambling, great weather, and ample opportunities to sit by the pool — sounds like an ideal retirement to us.