July's upswing in home sales might be a fluke, warn Realtors.

Home sales in Houston increased nearly 17 percent in July, and though Realtors and media outlets are downplaying its significance, instead referencing last summer’s home buyer tax credit as the true cause of the sale spike, there was positive data in the news about rentals and home values.

After the home-buyer tax credit expired  last summer, home values fell to their pre-credit lows, and the Houston market remained depressed through the beginning of 2011. Because of that, housing data in Houston is skewed, and Realtors and economists are unsure of how to interpret it.

As the Houston Association of Realtors (HAR) phrased it in a press release yesterday, “What do you get when you compare seasonal summer home buying in a single month to the same month a year earlier shortly after a home buyer tax credit expired? If it’s July 2011 in Houston, Texas, it’s a nearly 17 percent increase in home sales. Last year’s third quarter slowdown in home sales continues to make this year’s generally ‘typical’ real estate activity appear slightly more positive than it otherwise would be considered.”

Carlos Bujosa, the chairman of HAR, offered further perspective: “If you look at year to date numbers, last year versus this year were down about 2.2 percent. Again, if you look at 2009, a year that had no unusual circumstances, we’re down about 12.2 percent, so somewhere in between those two numbers is where we think the market probably is.”

One positive detail about July, though, came in the form of rentals, which were up 21 percent from July of 2010. Additionally, single family home values reached their highest level ever for a July, up almost one percent to $224,000.