The U.S. real estate market has been red hot of late. Data from The National Association of Realtors (NAR) shows that the median listing price of U.S. homes grew nearly 10% year-over-year in September 2017. Despite some reports of cooling in regional markets, other metropolitan areas are continuing to hit record high prices.

Above, we've plotted data from NAR's most recent monthly report. We look at the number of days that available properties spent on the market in the fifteen largest metropolitan areas in the country. As you might suspect, this number has been dropping the last several years. With high demand (and in some areas, short supply), real estate is being snapped up quicker in a hot market.

Not all metro areas follow this trend. In Miami, last month's inventory had been on the market for 22 more days than in September 2014. In other places like Houston, Detroit, and Phoenix, days on the market has stayed relatively stagnant over the last several years. Still, in 11 of the largest 15 metro areas, inventory has spent less time on the market year-over-year.

You can really see the seasonality of the real estate market in the graphic above. Over the last three years, inventory has been on the market for 36 more days in January than in June on average. The seasonal effect is even more pronounced in metro areas with harsh winters, like New York, Chicago, and Boston. Turns out that houses buried in snow don't sell very fast.