When many people think of vacant homes, they think of houses or apartments on the market for sale or rent. But the largest category of vacant housing in the United States is classified as “seasonal, recreational or occasional use,” commonly referred to as seasonal units.

These vacant structures cover a wide range of housing units, from part-time residences and hunting cabins to beach houses and timeshares.

As the nation recovered from the 2007-2008 housing crisis, the vacancy rate decreased from 11.4% in 2010 to 9.7% in 2020, according to 2020 Census Demographic and Housing Characteristics data released today.

In 645 of the nation’s 3,143 counties, seasonal units made up at least 50% of the vacant housing in the county. In 1,313 counties, seasonal units outnumbered the combined total number of units for rent or sale that were vacant.

The number of units for rent, units for sale, seasonal units and units that were in the vacant for some other reason category all declined during this period.

Despite that decline, there were still over 4.3 million vacant seasonal units throughout the country and seasonal units were once again the largest category of vacant housing (Table 1).

Table 1. U.S. Vacant Housing Units by Type: 2010-2020

The term “seasonal vacant” covers a wide swath of potential situations, so it’s not surprising such vacancies were found in every county in the country.

But while everywhere, seasonal vacants were more common in certain places.

While these counties included areas typically known as vacation or second-home destinations, they also included some of the country’s most populous areas.

Among the 15 largest counties by number of housing units, 11 had many more vacant units listed for rent than for any other vacant category, including New York County, New York; Harris County, Texas; Cook County, Illinois; and Los Angeles County, California (Table 2).

However, Riverside County, California; Broward County and Miami-Dade County, Florida; and Maricopa County, Arizona, had more vacant units that were for seasonal, recreational or occasional use than vacant units for rent or for sale.

Table 2. Top 15 U.S. Counties by Number of Housing Units: 2020

There were also 20 counties where over 90% of the vacant units were seasonal, including six in Wisconsin (Vilas, Burnett, Menominee, Florence, Sawyer, Oneida counties) and three in Colorado (Hinsdale, Mineral and Grand counties) (Table 3).

All 20 of these counties also had vacancy rates much higher than the national rate of 9.7%; all but six had a vacancy rate over 50%.

Table 3. Top 10 U.S. Counties With Highest Share of Seasonal Vacant Housing Units: 2020

The counties with the largest total number of seasonal units were in seasonal destinations, such as beach towns and ski resort areas.

Five of the top 10 counties were in Florida and two others were in New Jersey. Maricopa County and Riverside County were the only counties in the top 10 not located along a coast (Table 4).

Table 4. Top 10 U.S. Counties With Most Seasonal Vacant Housing Units: 2020

Despite the name, seasonal units cover a wide range of housing, including part-time snowbird housing in Maricopa County; second homes in New York County; hunting cabins in Vilas County, Wisconsin; and beach houses in Cape May County, New Jersey.

While it might seem complicated, the Census Bureau provides guidance to determine if a housing unit is vacant and, if so, how it should be classified.

The decennial census is the primary source of information on the type of vacant housing in your neighborhood but it’s not the only one. The Census Bureau’s Housing Vacancy Survey and American Community Survey monitor trends in vacant housing on a more frequent basis.

Evan Brassell is chief of the Housing Statistics Branch in the Social, Economic and Housing Statistics Division.