From the eia article Nearly 90% of U.S. household used air conditioning in 2020 by Ross Beall and Bill McNary (5/31/2022):
In 2020, the Midwest Census Region and South Census Region had the highest percentages of households using AC, at 92% and 93%, respectively. The lowest percentage of households using AC was 73% in the West Census Region; this census region includes households in several climate areas, such as the marine climate region along the Pacific Coast, where residential AC use was 49%.
The article cites the Residential Energy Consumption Survey, which is a nice data source.
