Open three tabs for Harrington Park real estate on the same afternoon and you will get three different answers to the same question. One site puts the median home value under $780,000. Another, pulling from the same New Jersey Multiple Listing Service, shows a 12-month median north of $1 million. A third quotes a listing median of $950,000 for March 2026. None of these sources is wrong. They are just measuring a market too small to hold still.
Harrington Park is a borough of roughly 4,800 people. In a typical 12-month stretch, only 36 to 37 homes change hands there. Some months produce a handful of closings. October 2025 saw just two sales, down from six the October before. When a statistic is built from a sample that small, it stops behaving like a market indicator and starts behaving like a coin flip. Two houses closing instead of six can move a published median by six figures without a single thing changing about how desirable the town actually is.
That is the piece missing from most Harrington Park guides. They quote the number. They rarely explain why the number won't hold still, or what a buyer or seller should be comparing instead.
What the disagreeing numbers actually show
Here is a snapshot of what different pages, pulling from the same underlying NJMLS feed at different moments, reported for Harrington Park across a recent stretch:
| Source & metric | Figure | Time window |
|---|---|---|
| Sold-homes page, trailing 12-month median | $1,027,000 | 12 months ending mid-2026 |
| Main listings page, trailing 12-month median | $985,000 | 12 months ending mid-2026, different snapshot |
| Same portal's affordability-calculator median | $912,000 | Same general period |
| A separate portal's listing median | $950,000 | March 2026 |
| A third portal's reported average sale price | ~$1.02 million | October 2025, up 9.8% year over year |
| A fourth portal's long-run value estimate | $776,900 | Undated automated estimate |
Every one of these numbers is a legitimate read on the same 07640 zip code. Three of them come from the very same portal, just cached at different moments, which is itself the point: even one source can't hold a stable number for this town, because the underlying pool of closings is too thin to average smoothly. The spread between the lowest and highest isn't a data error. It's what happens when a handful of closings a month gets asked to summarize an entire town's value.
Same streets, two different decades of houses
The reason the swings are so wide isn't just sample size. It's what's actually selling. Harrington Park's housing stock is unusually split between two eras standing on the same blocks.
On one end: modest split-levels and colonials from the postwar decades. One recent listing described an "oversized three bedroom, two and a half bath Sugar Maple Split Level" set on a quiet street just steps from the town's elementary school. Another sat a block from Highland Field. On the other end: brand-new construction filling in on the same streets, including a five-bedroom, 5.1-bath colonial with roughly 4,000 square feet of living space on a level third-acre lot, with a completion date in 2026.
Those two houses might sell six weeks apart, in the same zip code, to buyers with entirely different budgets and entirely different reasons for choosing the town. When one dominates a given month's closings, it drags the reported median with it. A town median calculated from three sales isn't describing "Harrington Park." It's describing whichever three houses happened to close.
This is the detail that matters if you're using a published median to size up your own opportunity. The number tells you almost nothing about a specific house you're considering. It tells you which vintage of home happened to trade recently.
The comparison that actually holds up
If the town-wide median is this noisy, what should a buyer comparing Harrington Park to a neighboring town actually look at?
Start with the fact that Harrington Park doesn't stand alone in the way school access is structured. Along with Northvale, Norwood, and Old Tappan, it sends students to Northern Valley Regional High School at Old Tappan, one of two high schools in the Northern Valley Regional High School District. Closter, Demarest, and Haworth feed the district's other campus, in Demarest. That means a buyer weighing Harrington Park against Old Tappan is choosing between two towns that share the same regional high school but sit at noticeably different price points. Old Tappan's average home value has been running near $1.26 million, up about 7 percent year over year, well above most of the Harrington Park figures in the table above.
The gap isn't explained by school access, since the high school is shared. It's explained by lot sizes, house vintage, and the pace of new construction in each town. That is the actual comparison worth making, and it has nothing to do with a headline median.
How to read Harrington Park's numbers without getting misled
A few habits protect you from anchoring on a number that happens to be noise this month:
- Ask how many homes closed in the window a statistic covers. A median built from three sales carries a different kind of confidence than one built from thirty.
- Sort by vintage and square footage before you sort by price. A 1960s split-level and a 2026-built colonial belong in different conversations, even on the same street.
- Compare the specific house to specific comparables, not to the town's headline number. Days on market and price per square foot for homes of similar age and size tell you more than any borough-wide average.
- When comparing towns, hold the shared variables constant. If two towns send children to the same regional high school, that removes one variable from the price gap and leaves you looking at lot size, house age, and inventory, which are the things actually driving the difference.
None of this requires distrusting the portals. It requires reading them the way you'd read any small-sample statistic: with an eye on how many observations built it.
What this means if you're the one selling
The same volatility that confuses buyers works in a seller's favor if you understand it early. In a town where only a few homes close most months, a well-prepared listing isn't competing against a stable, well-understood market price. It's competing against whatever comparable happened to sell last, which may or may not resemble your house at all. That is exactly the kind of ambiguity a clear pricing strategy and a well-documented comp set can resolve in a seller's favor, rather than leaving buyers to guess based on a portal number that doesn't reflect your home's vintage, size, or condition.
FAQ
Why do different real estate sites show such different numbers for the same town? Each site pulls from a different window of time and sometimes a different underlying dataset. In a low-volume market like Harrington Park, even a one- or two-sale difference in what closed that month can shift the reported median by tens of thousands of dollars.
Is Harrington Park's market actually less predictable than a bigger town's? Not less predictable in the sense of demand. Fewer transactions simply means each one carries more statistical weight, so any single closing has an outsized effect on the published average or median for that period.
Does sharing a high school district with Old Tappan mean the towns should be priced similarly? Not necessarily. Shared school access removes one variable from the comparison, but lot sizes, house age, and the pace of new construction differ enough between the two towns to explain most of the price gap.
If you're weighing a house in Harrington Park against one in a neighboring town, the comparison worth making isn't between two headline numbers. It's between two specific houses, read against the comps that actually match them. That's the kind of read that takes a working knowledge of the local inventory, not just a portal login.
If you'd like a second set of eyes on how a specific Harrington Park property compares to what's actually closing nearby, Rebecca Day offers a private consultation to walk through it.
