In September 2026, the median sale price of a detached single-family home in Deerfield was $908,000. That's 37.1% above the $662,500 median from September 2025, according to the Midwest Real Estate Data (MRED) Local Market Update for Deerfield. The same report shows the median for the twelve months ending September 2026 rising 9.2%, from $710,000 to $775,500. The 9.2% figure is the one that describes Deerfield's prices. The 37.1% figure is what happens when a median is calculated from 17 sales, and the same spike appeared in Northbrook and Highland Park that month. If you're comparing North Shore towns this fall, Deerfield stands out for a different reason. After its strongest twelve months in the data, new contracts fell by more than half in September. Attached homes are also the one segment where buyers are negotiating sellers below their original asking price.
Seventeen closings can't support a 37% story
Deerfield closed 17 detached sales in September 2026, down from 26 in September 2025. With 17 sales, the median is simply the ninth-highest price. If two or three larger homes close in a given month, the median can jump while the town's overall price level barely moves.
The average sale price shows this. The September average rose 17.3%, from $793,198 to $930,712, which is less than half the size of the median's jump. Over the trailing twelve months, the average and the median both rose about 10%, which is what a broad, real price increase looks like.
Deerfield detached, MRED data | September 2025 | September 2026 | Change |
|---|---|---|---|
Closed sales, single month | 26 | 17 | -34.6% |
Median price, single month | $662,500 | $908,000 | +37.1% |
Closed sales, trailing 12 months | 198 | 240 | +21.2% |
Median price, trailing 12 months | $710,000 | $775,500 | +9.2% |
Average price, trailing 12 months | $799,510 | $880,780 | +10.2% |
The twelve-month median is based on 240 sales, so it moves slowly. A swing of nine or ten percentage points in that figure takes a year of real price changes. MRED adds the same warning at the bottom of every local report:
"Activity for one month can sometimes look extreme due to small sample size."
Northbrook and Highland Park ran just as hot in the same month
If the September jump reflected something particular to Deerfield, the neighboring towns would look different. They don't. MRED's September 2026 updates for Northbrook and Highland Park show the same gap between the single-month median and the twelve-month median. Both reports carry data current as of October 14, 2026.
Detached homes | September 2026 median | Change vs. Sept. 2025 | Trailing 12-month median | Change |
|---|---|---|---|---|
Deerfield | $908,000 | +37.1% | $775,500 | +9.2% |
Northbrook | $1,300,000 | +52.9% | $900,000 | +9.1% |
Highland Park | $860,000 | +30.5% | $900,000 | +7.8% |
In September, all three towns posted single-month medians 30% to 53% above the prior year, while their twelve-month medians rose between 7.8% and 9.2%. Northbrook's $1.3 million September median came from 23 closings, and Highland Park's $860,000 came from 23. On twelve-month price growth, Deerfield, Northbrook and Highland Park are close to even. So price growth doesn't separate these towns this fall. The supply numbers below do.
What sets Deerfield apart is the pipeline
Deerfield's past twelve months were busier than its neighbors'. Detached closings in the year ending September 2026 rose 21.2%, to 240, and new listings rose 11.2%, to 327. In Northbrook over the same period, closings fell 8.0% and new listings fell 5.8%.
In September, Deerfield's trend went the opposite way from its neighbors:
- New detached listings in Deerfield fell 45.7%, from 35 to 19. Northbrook's rose 33.3%, from 42 to 56, and Highland Park's rose 21.9%, from 32 to 39.
- Homes going under contract in Deerfield fell 57.7%, from 26 to 11. Northbrook had 27 detached homes go under contract that month, and Highland Park had 30.
- Deerfield's month-end inventory held at 23 detached homes, compared with 24 a year earlier. Northbrook ended September with 51 and Highland Park with 39.
The contract count matters most for the figures still to be reported. A September contract usually turns into an October or November closing, so Deerfield's 11 detached contracts point to few late-fall closings. With so few, the monthly median will again come from a small set of sales and may swing up or down with little to do with prices. MRED doesn't publish a months-of-supply figure for Deerfield. Dividing 23 homes in inventory by 17 September closings gives a rough 1.4 months. That's a back-of-the-envelope ratio, but it describes a town with very few detached homes for sale.
Detached buyers this fall are competing for a short list
Fewer listings didn't make Deerfield sellers any more flexible. Detached homes that closed in September 2026 sold for 101.9% of their original list price after an average of 10 days on the market. A year earlier, the figures were 100.5% and 29 days. Over the trailing twelve months, buyers paid 101.7% of original list, and average market time fell from 34 days to 25. MRED's price figures don't account for seller concessions, so credits negotiated at closing aren't reflected in these percentages.
For a buyer weighing Deerfield against Northbrook, the numbers point to a few practical conclusions:
- Base your budget on $775,500, the twelve-month median. That figure comes from 240 sales. The $908,000 September figure comes from 17.
- Expect any detached house worth seeing to sell quickly. In September, Deerfield detached homes averaged 10 days on the market. Northbrook's averaged 38.
- Northbrook offers more homes to choose from. It ended September with 51 detached listings, more than double Deerfield's 23, and sold them at 103.2% of original list. A larger inventory there hasn't come with lower prices.
Townhomes and condos are where buyers have room to negotiate
Deerfield's attached market, which covers townhomes, condos and similar properties, shows much more room for negotiation. In September 2026, attached homes sold for 97.4% of original list price after an average of 35 days on the market. In September 2025, they sold in 18 days. Over the trailing twelve months, attached sellers received 97.9% of original list, down from 99.5% the year before. Deerfield ended September with 16 attached homes for sale against 5 closings that month. That's roughly 3.2 months of supply by the same rough calculation, more than twice the detached figure.
Attached prices kept rising during the same period. The twelve-month attached median rose 16.9%, from $325,000 to $380,000, which is a faster increase than detached homes saw. So attached buyers are paying more than they did a year ago while still negotiating below the original asking price. That suggests asking prices have climbed faster than buyers are willing to follow.
The neighboring towns don't show the same pattern:
Attached homes, September 2026 | % of original list received | Average market time |
|---|---|---|
Deerfield | 97.4% | 35 days |
Highland Park | 101.5% | 14 days |
Northbrook | 102.5% | 70 days |
Northbrook's attached homes sat for 70 days on average but still sold above original list. Highland Park's sold above list in two weeks. In Deerfield, attached buyers got below-list prices in September, and the trailing twelve-month figure says the same. For a downsizing seller or a buyer starting with a townhome, Deerfield is the town where the price difference gets negotiated.
FAQ
Why use MRED instead of state-level figures?Illinois REALTORS says it doesn't track prices for individual communities, and it reports county data quarterly. MRED's local updates break out detached and attached sales month by month for each town.
Should the next monthly median be expected to drop back? It could move sharply in either direction. Only 11 detached contracts were written in September, so the closings MRED reports for October and November draw from a small pool, and a small pool produces jumpy monthly medians. The trailing twelve-month median, $775,500 through September 2026, will change much more slowly.
Did Deerfield's detached sellers lose leverage when sales fell in September? The September figures say no. Detached homes sold for 101.9% of original list in 10 days, and inventory held at 23 homes. Fewer homes sold because fewer homes were listed.
If you're deciding whether to list a Deerfield home before winter or waiting for a townhome at the right price, the town's twelve-month figures and its current contract count say more than a single month's median. LWG Real Estate will put your property next to the actual Deerfield detached or attached figures and show you where it stands. Request a Home Valuation & Market Plan to get pricing built from the twelve-month numbers.
