September 2026 housing inventory report: active listings rose 11.4% in DuPage County and 6% in Lake County, yet months of supply stayed below 3, keeping markets tight at 7.03% 30-year rates.
As of late September 2026, the U.S. housing market continues to balance modest inventory gains against resilient demand. Redfin data shows national active listings grew roughly 3 percent year-over-year through August, while months of supply held near 4—still below the 5-to-6-month equilibrium range. The 30-year fixed mortgage rate, per FRED data released 24 September 2026, stood at 7.03 percent, the 15-year at 6.42 percent, and the 10-year Treasury at 5.18 percent, producing a 1.85-percentage-point spread that keeps financing costs elevated.
Local markets reveal a patchwork of supply and absorption. In DuPage County, Illinois, active listings climbed 11.4 percent to 3,607 and months of supply rose to 2.5 from 2.1 a year earlier, with the median home taking 51 days to sell. Lake County, Illinois posted a 6 percent increase in active listings to 3,039 and a 10.6 percent jump in new listings to 920; despite the added supply, months of supply actually tightened to 2.4 from 2.6, indicating demand outpaced supply growth. Median days on market remained essentially flat at 50 days.
| County (State) | Active Listings | YoY Change | Months of Supply | Median DOM | Source |
|---|---|---|---|---|---|
| DuPage (IL) | 3,607 | +11.4% | 2.5 | 51 | Redfin Aug '26 |
| Lake (IL) | 3,039 | +6.0% | 2.4 | 50 | Redfin Aug '26 |
| Davidson (TN) | — | — | 6.0+ | 62 | Redfin Aug '26 |
| Montgomery (TN) | — | — | 4.5 | 73 | Redfin Jul '26 |
Davidson County, Tennessee illustrates the opposite dynamic. Months of supply exceeded six, and the median home took 62 days to sell—well above the national average. Montgomery County, Tennessee showed 4.5 months of supply and a 73-day median DOM, with price growth slowing to 1.4 percent year-over-year. In both counties, realistic pricing remains essential; homes priced above recent comps linger longer.
Elevated financing costs continue to shape buyer behavior. With the 30-year fixed rate at 7.03 percent, monthly payments on a $400,000 loan are roughly $530 higher than they would be at 2021 averages. The spread between the 10-year Treasury and the 30-year mortgage—1.85 percentage points—reflects persistent lender caution. HomeRates.ai users can run live scenarios at HomeRates.ai to see how rate movements alter qualifying payments in real time.
Inventory gains are geographically uneven and remain insufficient to shift most markets into buyer territory. Unless new listings accelerate or mortgage rates decline meaningfully, months of supply is likely to stay below equilibrium through year-end. Sellers who price competitively and buyers who secure financing early will continue to navigate a competitive landscape.
Housing inventory 2026 is up modestly in suburban Chicago and other pockets, yet months of supply below three in many counties keeps the market tight. Track weekly Redfin and FRED releases and model payments at HomeRates.ai before entering contract negotiations.
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