Where air conditioning is most — and least — common in Montana

On July 12, Miles City saw record-breaking heat of 115ºF, according to the National Weather Service. 

Happily for locals, that heat came in a county where residential air conditioning is more common than anywhere else in Montana, according to 2023 data released by the U.S. Census Bureau this year. 

An estimated 95.5% of occupied homes in Custer County, where Miles City is the county seat, had air conditioning in 2023. That’s the highest percentage among Montana’s 56 counties. Statewide, about 73% of occupied homes had some form of air conditioning, the fifth-lowest rate of any state.

The figures come from the Census Bureau’s new Local Air Conditioning Estimate (LACE) data series, which saw its first release earlier this year. The experimental data product provides estimates of air-conditioning availability at the national, state, county and census tract levels.

The data show substantial differences across Montana, with air conditioning generally more common in the eastern half of the state.

Of the 5,044 households surveyed in Custer County, only 227 didn’t have air conditioning.

Nearby Dawson County had the second-highest percentage of occupied homes with air conditioning, at 94%, followed by Yellowstone County at 93.9%.

On the other side of the state, Deer Lodge County had the lowest estimated prevalence of air conditioning in Montana. Just 44.6% of its occupied homes had air conditioning of any kind, leaving more than 2,500 of the county’s 4,500 households without.

Powell, Meagher, Granite and Sanders counties also had air-conditioning rates below 50%.

The variance extends to Montana’s most populous counties as well. Yellowstone County in the southeastern part of the state had air conditioning in 93.9% of occupied homes, compared 81.2% in Gallatin County, 71.6% in Missoula County and 65.9% in Flathead County. Those rates fit an overall trend in which the farther north or west a county is, the lower its rate of air conditioning tends to be.

Montana’s overall air conditioning prevalence trailed all neighboring states. The Census Bureau estimated that 97.9% of homes in North Dakota had AC, as did 95.4% in South Dakota, 90.7% in Idaho and 78.9% in Wyoming. 

The Census Bureau developed the Local Air Conditioning Estimate data by combining information from the American Housing Survey, which includes a question about air conditioning, with the larger American Community Survey. The resulting model estimates how many occupied homes, apartments and other dwelling units have any kind of air conditioning, including central and individual-room systems.

Because 2026 marks the first release of this data series, historical comparisons are not yet available.

The Census Bureau says the new data can help local governments and emergency planners identify communities where limited access to cooling could increase vulnerability during extreme heat events.