Southlake's $525,000 Median Jump Came From 36 Sales. The Real Shift Is in New Listings.

How much did a Southlake home gain in value over the past year? Read the September 2026 MLS report on its own and you would say about 44 percent. The single-family median rose to $1,725,000 from $1,200,000 in September 2025. A buyer who sees that figure may assume they have to stretch above asking. The same row shows the opposite. Southlake homes sold in September 2026 closed at 95.2 percent of list price, and the typical home sat 49 days.

The headline median moved because of which homes sold. Underneath it, fewer owners have been listing all year, and that change is real.

Thirty-Six Sales Can Swing a Median

A median is the middle sale in a month's closings. In a city of estates, the middle home in one month can look very different from the middle home in the next. In September 2026, Southlake recorded 36 single-family closings. In September 2025 it recorded 18. The comparison month was thin to begin with. Southlake had 52 closings in July 2025 and 43 in August 2025, so a September with 18 sales was an unusually quiet base to measure against.

The September 2026 average price was $2,181,579, well above the $1,725,000 median. An average that high above the median points to a handful of very large closings pulling the month upward. That reflects the homes that happened to sell. It does not show every Southlake home gaining in step.

Colleyville shows the same effect running the other way in the same report. Its September 2026 median fell to $800,000 from $1,000,000 a year earlier, on 19 closings compared with 28. Colleyville estates did not lose a fifth of their value over the summer. When only a few dozen homes sell in a month, a few sales at the top or bottom can swing the median sharply in either direction.

There is one more caveat. The report notes that the current month's sales count is a projection of the final total once every closing is entered in the MLS. It also counts only NTREIS listings, so builder sales outside the MLS are left out. September's 36 closings could still be revised.

Nine Months of Southlake on One Page

A single month can mislead, but a run of months gives a steadier picture. Here is Southlake's single-family row from each NTREIS Monthly MLS Summary Report in 2026, prepared by the Texas Real Estate Research Center at Texas A&M University.

From January through August 2026, the median stayed between $1,326,000 and $1,525,000. That is a fairly tight range for a city where one estate closing can shift the middle of the month. March and September each had 36 closings, yet their medians were $375,000 apart. The number of sales was identical. The homes that sold were not.

Price per square foot also rose in September 2026. The median reached $400.63, up from $347.57 in August and $379.46 in June. That figure is affected by the mix of sales too. Newer construction, larger lots and finished-out estates all carry a higher price per foot. One month of 36 sales cannot separate a real price change from a richer batch of homes. Buyers should treat the September figure as a reading to confirm against the months that follow.

The Number That Changed Is How Many Owners Listed

The year-over-year comparisons are clearest on the supply side. In most months from April onward, fewer Southlake owners put their homes on the market than a year earlier:

• April: 78 new listings, down from 96
• May: 63, down from 92
• June: 50, down from 73
• July: 49, compared with 46
• August: 30, down from 43
• September: 37, the same as a year earlier

Across those six months, Southlake had 307 new listings in 2026, compared with 387 over the same months of 2025. That is about a fifth fewer homes coming to market. The pile of homes for sale shrank as a result. Active listings were 170 in May and June 2025. They held between 141 and 146 from April through July 2026, then dropped to 115 in September 2026. Months of supply fell from 5.7 in June 2025 to 3.5 in September 2026.

Unlike the median, these figures do not depend on which homes happened to close. Each one tracks every listing that entered or sat on the market, so it is far less affected by a few big sales. A buyer shopping in Southlake this fall has fewer homes to choose from than a buyer a year ago. On the seller side, an owner listing now faces less direct competition than one listing in the spring of 2025.

Thinner Supply Has Not Ended Fall Negotiating

If tighter supply alone set prices, sold-to-list ratios would be climbing. They follow the calendar instead. In April and May 2026, Southlake homes closed at 98.2 and 98.5 percent of list price. By August and September they closed at 94.3 and 95.2 percent. 2025 followed the same arc, falling from 98.4 percent in April to 92.9 percent in August and 91.7 percent in September.

That gap of roughly three percentage points between spring and fall closings means real money. On a $1.4 million list price, it comes to about $42,000. Time on market tells the same story. Typical days on market rose from 26 in March 2026 to 49 in both August and September. A listing that has been on the market for seven weeks usually has a seller who is more willing to talk than one listed for three.

Both years point the same way. Fewer listings have made Southlake tighter than it was a year ago, and the fall season still gives buyers room. Sold-to-list in September 2026 was higher than in September 2025, so that room has narrowed somewhat. It is still there.

Where Southlake Sits Among Its Neighbors

Comparing Southlake with its neighbors in the same September 2026 report shows how relative the word "tight" is:

Southlake has tightened more than any of these markets over the past year, yet it still has more months of supply than Colleyville, Keller or Grapevine. Its 115 active listings in September 2026 give a buyer a wider field than the headline median suggests. Keller had 64 closings that month, so its $700,000 median rests on a deeper set of sales than Southlake's figure. Colleyville's 75 days on market and 93.5 percent sold-to-list show even more fall room there than in Southlake.

The September report was dated October 7, 2026, so the October numbers should follow a similar schedule in early November. When they arrive, three checks will show whether September was a turning point or a one-month spike:

1. Whether the Southlake median stays near $1.7 million or returns to the $1.33 million to $1.53 million range it held from January through August.
2. Whether new listings keep running below the 2025 pace, which keeps supply tight heading into winter.
3. Whether sold-to-list stays in the mid-90s, which would show that fall buyers still have room on price.

If you are weighing an offer in Southlake this fall or deciding whether to list before spring, Marcontell-Gilchrest Group can walk you through the recent closings behind the street or price range you are considering. Contact Us to talk through what September's numbers mean for your next move.