Annual median $/SF is the typical price per square foot for homes that closed in the city over the twelve months ending on the date in the heading: half sold for more per square foot and half for less. Last year is the same figure for the twelve months before that, so comparing the two columns shows how much prices per square foot have changed.
ARMLS closings is how many homes sold in the city over those twelve months. The median $/SF beside it is worked out from those sales, so the more closings, the more reliable the figure. A city only appears once it has at least 20 closings in the period. Hover over a city to see how many it had the year before. Tap a city to see how many it had the year before.