In one sentence a reporter can quote: New York City tenants have filed 84,749 mold complaints since the start of 2024, and the city is still carrying 36,158 open HPD mold violations — 86% of them classified Class B or C, the “hazardous” and “immediately hazardous” tiers.
Key Findings (2024–2026 data)
- 84,749 mold complaints have been filed through NYC’s 311/HPD system since January 2024 (complaint type UNSANITARY CONDITION, descriptor MOLD).
- The city is carrying 36,158 open HPD mold violations right now. Mold is rarely treated as cosmetic: 86.4% are Class B (hazardous, 26,627) or Class C (immediately hazardous, 4,615) — only 13.6% are the non-hazardous Class A.
- Mold complaints dipped 8.9% citywide in 2025 (34,518 → 31,435) — but Manhattan was the only borough where they rose, up +2.6%.
- The Bronx leads every borough — 10,812 mold complaints in 2025, 34% of the citywide total.
- But the single most mold-complained neighborhood is in Manhattan: Washington Heights (1,653 in 2025), and the fastest-rising mold neighborhoods are mostly Manhattan too (East Harlem +23%, Upper West Side +15%).
- Unlike evictions, mold is geographically spread. Manhattan neighborhoods (Washington Heights, Harlem, the Upper West Side) show up as often as the Bronx among the buildings with the highest complaint rates per unit.
- The building with the highest mold-complaint rate is 2069 Walton Avenue in Fordham, the Bronx: 191 mold complaints across just 33 units since 2024 — nearly six per apartment.
- Complaints are seasonal — they peak from July through October (August is the single busiest month) and bottom out in late spring.
Mold complaints by year
| Year | Mold complaints |
|---|---|
| 2024 | 34,518 |
| 2025 | 31,435 |
| 2026 (partial, through mid-year) | 18,796 |
Citywide, mold complaints fell 8.9% from 2024 to 2025. The 2026 partial-year figure (18,796 through mid-year) is running close to the same annualized pace.
Most mold complaints are “hazardous” violations, not cosmetic
Where a complaint is inspected and confirmed, HPD issues a violation with a hazard class. Mold violations skew heavily toward the hazardous end:
| Class | Meaning | Open mold violations | Share |
|---|---|---|---|
| B | Hazardous | 26,627 | 73.6% |
| C | Immediately hazardous | 4,615 | 12.8% |
| A | Non-hazardous | 4,916 | 13.6% |
| Total | 36,158 |
More than five in six open mold violations (86.4%) are Class B or C. That is the clearest signal in the data that mold, in NYC’s enforcement records, is a health-and-safety issue rather than a housekeeping one.
Mold complaints by borough (2025)
| Borough | 2025 | 2024 | YoY |
|---|---|---|---|
| Bronx | 10,812 | 12,407 | −12.9% |
| Brooklyn | 9,371 | 10,345 | −9.4% |
| Manhattan | 6,712 | 6,540 | +2.6% |
| Queens | 3,911 | 4,479 | −12.7% |
| Staten Island | 629 | 747 | −15.8% |
The Bronx accounts for 34% of all 2025 mold complaints — the same borough that leads the city on evictions and open HPD violations. But the year-over-year direction is the surprise: complaints fell in four of five boroughs, and Manhattan was the lone exception, where they rose.
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width="700" height="500" style="border:0;max-width:100%"></iframe>Mold complaints by neighborhood (2025)
Zooming from boroughs to neighborhoods confirms the spread. Washington Heights (Manhattan) has the most mold complaints of any NYC neighborhood — more than any Bronx neighborhood — and Manhattan and the Bronx trade places at the top of the list.
| Neighborhood | Borough | 2025 | 2024 | YoY |
|---|---|---|---|---|
| Washington Heights | Manhattan | 1,653 | 1,815 | −8.9% |
| Highbridge | Bronx | 1,628 | 1,690 | −3.7% |
| Fordham | Bronx | 1,541 | 1,808 | −14.8% |
| Kingsbridge Heights | Bronx | 1,355 | 1,603 | −15.5% |
| Harlem | Manhattan | 1,312 | 1,314 | −0.2% |
| East Flatbush | Brooklyn | 1,113 | 1,264 | −11.9% |
| Belmont | Bronx | 1,088 | 1,124 | −3.2% |
| Flatbush | Brooklyn | 1,052 | 1,138 | −7.6% |
| Williamsbridge | Bronx | 957 | 1,156 | −17.2% |
| Bedford-Stuyvesant | Brooklyn | 922 | 934 | −1.3% |
Where mold complaints rose — and fell — the fastest (2024 → 2025)
Citywide mold complaints dipped, so most neighborhoods fell. But the neighborhoods that rose tell the Manhattan story: among neighborhoods with a meaningful base (≥300 complaints in 2024), three of the five fastest risers are in Manhattan.
Rose the fastest
| Neighborhood | Borough | 2024 → 2025 | YoY |
|---|---|---|---|
| East Harlem | Manhattan | 648 → 797 | +23.0% |
| Canarsie | Brooklyn | 310 → 371 | +19.7% |
| Upper West Side | Manhattan | 435 → 499 | +14.7% |
| Morrisania | Bronx | 853 → 897 | +5.2% |
| Upper East Side | Manhattan | 351 → 365 | +4.0% |
Fell the fastest
| Neighborhood | Borough | 2024 → 2025 | YoY |
|---|---|---|---|
| Pelham Parkway | Bronx | 751 → 520 | −30.8% |
| Riverdale | Bronx | 591 → 432 | −26.9% |
| Rockaway | Queens | 524 → 392 | −25.2% |
| St. George | Staten Island | 534 → 418 | −21.7% |
| Soundview | Bronx | 977 → 767 | −21.5% |
The pattern is consistent with the borough numbers: mold complaints are easing in the Bronx and Staten Island while rising across Manhattan — East Harlem, the Upper West Side, and the Upper East Side all climbed.
Buildings with the highest mold-complaint rates (per 100 units, 2024–present)
Raw complaint counts mostly track building size. Normalizing by unit count reveals where mold is actually concentrated. Rate = mold complaints per 100 residential units since January 2024 (buildings with ≥20 units and ≥15 mold complaints).
| Building | Neighborhood | Complaints / units | Per 100 units |
|---|---|---|---|
| 2069 Walton Avenue | Fordham (Bronx) | 191 / 33 | 578.8 |
| 134 West 82 Street | Upper West Side | 74 / 20 | 370.0 |
| 772 East 168 Street | Morrisania (Bronx) | 97 / 60 | 161.7 |
| 80 Clarkson Avenue | Flatbush (Bklyn) | 129 / 83 | 155.4 |
| 2153 Amsterdam Avenue | Washington Heights | 34 / 23 | 147.8 |
| 148 West 124 Street | Harlem | 28 / 20 | 140.0 |
| 5510 13 Avenue | Borough Park (Bklyn) | 52 / 38 | 136.8 |
| 21 Pennsylvania Avenue | East New York (Bklyn) | 25 / 20 | 125.0 |
| 2302 Valentine Avenue | Fordham (Bronx) | 30 / 24 | 125.0 |
| 2268 Washington Avenue | Belmont (Bronx) | 25 / 20 | 125.0 |
Notice the mix: the per-unit leaders span the Bronx, Manhattan, and Brooklyn — mold is not confined to one borough the way evictions are. (By raw count the leaders are the city’s largest complexes — 16 Richman Plaza in the Bronx (271 complaints across 1,654 units) and the Metropolitan Oval buildings in Parkchester — but those are among the biggest residential buildings in the city.) You can look up the full complaint and violation history for any NYC building at 311tracker.com.
When mold complaints peak
Mold complaints are seasonal. Averaged across 2024–2025, they climb through the humid late-summer months and stay elevated into the fall, then fall back in spring:
| Month | Mold complaints (2024–2025) |
|---|---|
| January | 6,115 |
| February | 4,631 |
| March | 5,274 |
| April | 4,389 |
| May | 5,396 |
| June | 4,334 |
| July | 6,386 |
| August | 6,504 |
| September | 6,129 |
| October | 6,044 |
| November | 5,208 |
| December | 5,543 |
The July–October window is consistently the busiest — August is the single highest month — which tracks with peak summer humidity. Late spring (April and June) is the quietest.
Methodology
Mold complaints are counted from NYC 311/HPD service requests with complaint type
UNSANITARY CONDITION and descriptor MOLD, covering January 2024 to mid-2026, keyed to each
building’s BBL. Open HPD mold violations are counted from the hpd_violations table where the
violation description references mold; counts reflect open violations (closed violations are not
retained). Borough, neighborhood, building, and hazard-class breakdowns are computed directly from 311tracker’s
database. Cite as: “According to 311tracker.com, [stat].”
More from the NYC Housing Data Reports collection: the NYC Evictions Report and the NYC Rat Report.
311tracker.com is a free tool tracking 311 complaints, HPD violations, evictions, and rat-inspection history for all 834,400 NYC buildings. No signup required.