These 10 states have the least air-conditioning as heat waves roast the U.S.

This weekend much of America was again blanketed in a heat wave. As Reuters noted, over 175 million Americans were under excessive heat warnings and advisories. This led many major cities including Chicago, New York, and Philadelphia to open cooling centers in public buildings and libraries where people could seek shelter in air-conditioned spaces if they lacked the technology in their own homes.

But just how many homes in America are without air-conditioning? Thanks to Lucas Davis, a professor of business and technology at the Haas School of Business at the University of California, Berkeley, we have some idea.

During last year’s heat wave, Davis looked at data from the 2020 Residential Energy Consumption Survey (RECS), which the U.S. Department of Energy conducts every four years. Using data from the 2020 RECS that was collected from nearly 18,500 households—statistically representative of the 123.5 million primary household units in the United States—Davis was able to map the percentages of households that had air-conditioning, based on state. 

As the data revealed, an overwhelming majority of primary residences in the United States had air-conditioning:

In 40 states, more than 80% of primary residences had AC.
In 32 states, more than 90% had AC.
And in 13 states, more than 95% had AC.

But what about the laggards, or the states with the fewest number of primary AC-equipped residences? Davis looked at that data, too, and found the states with the least air-conditioning are:

Alaska (7%)
Washington (53%)
Hawaii (57%)
Montana (65%)
Vermont (67%)
Maine (70%)
Wyoming (71%)
California (72%)
Oregon (76%)
New Hampshire (77%)

Alaska is the standout with just 7% of primary residences having AC. However, given its northerly location, it’s understandable that most homes just don’t need air-conditioning. As for the state with the most primary residences without AC, California tops the list due to its population density. There are 14 million households that are without AC.

Of course, these numbers are from the 2020 RECS, which is still the most current. When the next survey comes out, it’s highly likely that AC unit numbers will have increased in most states given that America has had year after year of sweltering heat waves since the turn of the decade, and those heat waves are only likely to become more frequent in the years ahead.