It’s a seller’s sprint in the Big Apple.

New York homeowners flung open their doors in September, putting 4,951 properties up for sale across the five boroughs, according to a new StreetEasy report. That’s the biggest monthly haul since the spring of 2022 and a 7.6% jump from a year earlier.

The timing is no accident. Owners are betting that eager buyers and a bone-dry supply of homes will keep prices propped up, even as the cost of borrowing keeps creeping higher.

“Sellers are running to take advantage of a market where buyer competition is still hot and inventory is still tight,” Kenny Lee, senior economist at StreetEasy, told The Post. “Even with mortgage rates climbing, more than one in five homes sold above asking in September, so sellers see a window and are moving.”

That window could be narrowing. The national 30-year fixed mortgage rate punched past 7% in late September for the first time since January 2025, then climbed to an average of 7.28% at the start of October, up from roughly 6.3% a year ago, per Freddie Mac.

Buyers are already feeling the squeeze. Signed contracts fell 5.4% citywide to 1,528 last month, with Manhattan down 6.8% to 660 and Brooklyn tumbling 11.5% to 415. Homes are also lingering longer, with the typical property now sitting 88 days before a deal, two weeks more than last fall. The citywide median asking price slipped 5.2% to $995,000.

Queens was the rare bright spot. Contracts there rose 9.3% to 353, powered by a 12.4% spike in co-op deals.

But don’t call it a buyer’s market just yet. More than 21% of homes still fetched above their asking price, a slight uptick from a year ago. And despite the listing bonanza, overall inventory dropped 4.9% to 16,737 homes, extending a losing streak that has run every single month of 2026.

Long Island City blew every other neighborhood out of the water. New listings there more than tripled, soaring 205.4% to 113 homes as a string of new developments opened sales. The median ask came in at $1.14 million.

Flatiron grabbed the No. 2 spot with 99 new listings, a 67.8% leap, at a median price of $2.725 million. Tribeca followed with 81 listings, up 30.7%, carrying an eye-watering median ask of $5.1 million.

On the more affordable end, Washington Heights saw listings climb 42.1% to 54, with a median price of just $539,500. Astoria jumped 28.4% to 95 homes at a median of $999,000, while Williamsburg added 109 listings, up 26.7%, at $1.45 million.

The Upper East Side remained the volume king by a mile, with 603 new listings, up 17.5%.

In Manhattan, the action is coming from people who already own. Resale condo listings surged 15.8% to 1,054, while brand-new sponsor units shrank 18% to just 155 as fewer towers make it out of the ground.

“While neighborhoods like Long Island City saw surges in new listings driven by new development launches, the pipeline of new developments across the city is starting to dry up,” Lee said. “That means that many neighborhoods, like the Flatiron District, are seeing jumps in new listings primarily from condo owners cashing in on resilient demand for resale condos.”

Meanwhile, would-be buyers spooked by rates are staying put as tenants, and that’s making life miserable for everyone hunting for a lease.

Rental inventory plunged 15.3% to 29,029 units, the steepest annual drop in four years. Manhattan’s median asking rent held firm at $4,995, up 8% from last year and shrugging off the usual post-summer dip. Brooklyn’s rental supply shriveled 18.4%, with the median rent there climbing to $3,945, while Queens hit $3,400.