U.S. home prices hit another record high in June, even as buyers backed out of deals and stood on the sidelines. This should be the busiest time of year, but the housing market remains frozen in place and sales are down.

Last month, sales of existing homes dropped by 2.7 percent from the previous month, while the median home price, at $435,300, hit a record high for the month of June, according to the National Association of Realtors.

June is supposed to be the height of the spring housing season, the time of year when Americans move before their attention shifts to summer vacations, the next school year and the winter holidays. Sales typically pick up again in the fall, but not enough to compensate for a lackluster spring. And this spring has been anything but active. In a sign that buyers are skittish about making a large purchase in an uncertain economy, about 15 percent of June deals fell apart, the highest level for the month of June on record, according to Redfin.

“What it really comes down to, as always, is affordability,” said Daryl Fairweather, the chief economist at Redfin. Buyers, she said, “just don’t feel like they can afford to buy a home at these prices.”

This disconnect between home prices and home sales has defined the last three years of the housing market, and kept it in a doom loop. June was the 24th straight month of year-over-year price growth in the United States, yet regions like the Northeast saw the number of sales plummet by 8 percent in June from the previous month, according to N.A.R. These conditions are the result of a combination of a lack of available homes to buy and stubbornly high mortgage rates, creating an affordability crisis for millions of Americans who have been all but shut out of the housing market for three years.

The 30-year mortgage rate has been stuck just below 7 percent since November, and was 6.75 percent as of July 17, according to Freddie Mac, the mortgage finance company. Mortgage rates, which tend to track to the 10-year Treasury yield, reached a recent peak in January and are unlikely to fall soon.