San Antonio boasts one of the hottest real estate markets in the country. Brandon Seidel/Shutterstock Real estate is a competitive business. In some markets, if you don't jump on a property you like right away, you risk losing it within days — or even hours.

A new study by Realtor.com found the hottest housing markets in country by zip code, measuring the time it takes properties to sell and how frequently homes are viewed.

Homes in the hottest zip codes go fast, selling in an average of 25 days — a full 53 days faster on average than the rest of the country, according to Realtor.com. These places also have a few crucial similarities: They tout strong job markets and are home to a large population of millennials, one of the largest generations in US history.

Notably, the top three places — Watauga, Texas; Pleasant Hill, California; and Northglenn, Colorado — are all located along the perimeter of major metro areas: Fort Worth, San Francisco, and Denver, respectively. These peripheral locations allow buyers to purchase relatively affordable homes within expensive metro areas, according to the report.

Read on to check out the 20 hottest housing markets in America by zip code.