Statistics released a few months ago indicated that the median price for single-family homes in the Washington area stagnated at the end of 2004 and the beginning of 2005, and this column speculated that the long rally in local housing prices might finally have cooled.

Never mind.

The National Association of Realtors has released data on sales completed in the second quarter of 2005 and they show a dramatic rally in the price of local single-family homes, to a median of $429,200. That's up 26.2 percent from the $340,100 median price in the second quarter of 2004 and it's up sharply from $380,600 in the first three months of 2005.

This comes despite anecdotal and statistical data that suggest the local housing market is cooling this year. Houses are sitting on the market longer and more are being put up for sale. Last week, seemingly contradictory data emerged, with the NAR reporting that sales of existing homes dipped in July and a Commerce Department study the next day showing that sales of new homes soared that month.

The real lesson in the fluctuating local data on home sales and in the seemingly contradictory national indicators is that truism of economic analysis: You can't be sure about what will happen tomorrow just by knowing what happened yesterday.

-- Neil Irwin