Islip, NY real estate agent.

The Secatogue were here first, with principal villages at what became West Islip, Bay Shore and Oakdale. On November 29, 1683, William Nicoll — son of a New York City mayor — purchased a patent from Winnequaheagh, Sachem of Connetquot, and named the roughly fifty thousand acres Islip Grange. His domain eventually reached from East Islip out to Bayport, taking in Sayville, Oakdale, Great River, Holbrook, Bohemia, Holtsville and more.

But not this piece. According to the Islip Hamlet Historical Society, Nicoll's patent surrounded the land between the two creeks and deliberately left it out. In the 1690s an attorney named Andrew Gibb — a colleague of Nicoll's — applied for that gap himself, and on March 26, 1692 Governor Richard Ingoldsby granted it to him in the names of William and Mary: the tract bounded by Champlin's Creek to the east and Orowoc Creek to the west, some 3,500 acres.

Gibb's parcel was a fraction of Nicoll's, but it was the useful fraction. It became the commercial center of the area and then the seat of the town government, which is why the smallest patent ended up with the courthouse and the name.

The railroad reached the town in 1844, and the South Side Railroad line of 1868 opened the bayfront hamlets to summer traffic. The town's population was around 2,600 in 1850. After the Second World War it went vertical — roughly 71,000 in 1950 to 278,000 by 1970 — and today the Town of Islip holds 339,938 people across nearly 163 square miles.

The hamlet did not do that. Islip proper covers about five and a half square miles and counted 18,418 residents at the 2020 census, fewer than it had in 2000. So the same word describes a place of eighteen thousand and a place of three hundred and forty thousand, and almost nothing said about one applies to the other. Seatuck National Wildlife Refuge occupies the hamlet's southeastern corner, and the Islip Union Free School District runs its five schools from offices on Main Street.

West along Montauk Highway you reach Bay Shore and then West Islip; east runs through East Islip to Oakdale, where my office is, and on to Sayville. The communities I work in are on the service area page.

The year in two parts

From September through February, 47 Islip homes sold at a median of $735,000, taking a median 27 days to go into contract. From March through August, 56 sold at a median of $695,000, in 22 days.

Read those two lines again. Three of the towns I pull data for saw a lower median in the second half than the first, and Islip's was much the steepest of them. Nearly everywhere else the spring lifted prices, in most cases by three to eight percent. Here the median went the other way, by about 5%.

I wouldn't turn that into a forecast. It's one year, a hundred sales, and a different set of houses in each half. But it's worth knowing that Islip didn't get the lift that Bay Shore, West Islip and Sayville all got over the same months, and a seller here shouldn't assume the market will carry them upward while they wait.

Getting the price wrong costs more time here than anywhere else

66 of the 103 sellers closed at or above the price they first asked. Taken seller by seller, the typical Islip home finished about $6,000 above its own asking price, a shade under 1%.

That's a thin margin, and it means very little is being bid up. What the data does show is a sharp difference between sellers who held their original price and sellers who later reduced.

The 66 who held their original price went into contract in a median 17 days. The 37 who had to reduce their initial price took 65 days and finished about 4% below where they opened.

Seventeen days against sixty-five. That 48-day gap is the widest of any town in this data, and I checked every town I drew data for. Two and a half months of showings, and a lower number at the end of it.

In a market where the second-half median was lower than the first, I wouldn't assume appreciation will rescue an ambitious opening price. The 17-day versus 65-day split is a much stronger reason to start with a number the comparable sales support.

The middle of the market is where Islip is strongest

The $650,000 to $800,000 band is the best place to be. Those homes went into contract in twenty days and closed about 4.5% above their asking price, with three in four sellers getting their number. I'm not suggesting you price a $900,000 house at $800,000 to move it quickly. Please don't take that as the lesson here.

Either side of it the market flattens out. Below $650,000 and above $800,000 the typical sale landed within a rounding error of the asking price, and closer to three in five sellers got what they asked.

The three groups are almost the same size, so this isn't a town with one dominant price point. It does mean that where your house sits in the price range changes what you should expect, and the strong middle is narrower than most sellers assume.

Search-price thresholds still matter

Buyers often set maximum search prices at round numbers, so a home just above one can miss buyers who would otherwise consider it. In this Islip data, 100 of 171 listings were positioned just under a round number.

That's useful when choosing among reasonable asking prices, but it doesn't replace valuation. Islip's much bigger pricing lesson is the 17-day versus 65-day difference between sellers who held their original price and those who had to reduce.

The listings that did not sell

Eighteen Islip listings ended the year unsold and haven't come back on yet. That's about one in seven of everything put on the market here.

Eighteen is a number I can report but can't lean on. Where a town gives me forty or fifty I can look at what those sellers asked, whether they ever moved off it, and where in the price range they sat. With eighteen I'd be describing a handful of specific houses and dressing it up as a market pattern.

What the 48-day gap higher up this page does tell you is that Islip gives a mispriced listing a long time to sit there. Whatever went wrong for those eighteen, this isn't a market that corrects it quickly on the seller's behalf, especially if the problem was pricing.

Price isn't the only possible cause. Presentation, photography, showing access, listing accuracy, property condition and transaction issues can all affect whether a home sells, and none of that is visible in a basic data export.

That's the reasoning behind the written cancellation guarantee I give every seller. If the listing isn't working and we can't fix it between us, you shouldn't be held to it.

What the market looks like right now

13 Islip homes are on the market at a median asking price of $699,999, which is about 3% below where sales have actually been closing. Another 22 are in contract.

That's an unusual position. In most towns the homes currently listed are asking above the recent closings. Here they're asking under. With only thirteen listings I wouldn't read too much into the figure itself, but it doesn't suggest a market where sellers are reaching.

Only 2 of the 13 have passed 90 days without going into contract, and there are more homes in contract than available to buy. So very little is stuck and the pipeline is working.

Put the year together and the picture is consistent: the second-half median was lower, the group that held its original price reached contract much faster than the group that reduced, and very little current inventory is beyond 90 days. That argues for a defensible opening number without turning the group comparison into a guarantee for any individual home.

None of this tells you what your own house is worth. I can give you a price range from the sales without seeing it, but a firm number means walking through the house and setting it beside what a buyer would really be choosing between.

Source: OneKey MLS, September 2025 through August 2026; homes for sale, in contract, and off the market as of early September 2026. These figures describe Islip as a whole and are not an estimate of any individual property's value.

The written cancellation guarantee isn't something I hold back for sellers who think to ask about it. Everybody gets one. The rest of it is on the seller page.

I prepare valuations personally rather than relying on an automated estimate.