New York City renters face varying unsafe housing conditions, like insufficient heating, rats, and illegal dumping. Renters can complain to 311 anytime their building violates standard living conditions, and in New York, landlords must keep their residences free of moisture. However, many renters face recurring instances of mold, leading them to report the issue to the city.
Mold raises health concerns, such as headaches and itchy eyes, but in more serious cases, it can cause fungal infections that require diagnosis and treatment. Mold also damages property, as repeated instances indicate excessive moisture that could develop into unsafe structural issues. To find out how much New Yorkers combat mold issues, RentHop looked into 311 complaints about mold from 2017 through June 8, 2025. The results show that more renters have filed complaints about mold in recent years. Continue reading to learn if you live in an area with a high volume of mold complaints.
Key Findings
- The Bronx is New York City’s moldiest borough, with 304.3 complaints per 10,000 residents.
- Flatbush receives the most mold complaints, averaging 623.6 complaints per year.
- September 2021 received the most mold complaints on record since 2017, coinciding with when Hurricane Ida flooded residences and increased moisture levels.
- Month-over-month, renters complain most about mold in the late summer and early fall months.
- 2024 was the moldiest year on record, with 36,178 complaints citywide.
- Monthly complaints in 2025 are lower than 2024, but this summer’s warm weather could lead to more complaints by the end of the year.
Mold Complaints by NYC Borough
The above chart breaks down the number of mold complaints by year by borough. The Bronx has received the most complaints yearly since 2019. Last year, the borough received 12,937 complaints, or 304.3 reports per 10,000 renter-occupied units, making it the moldiest borough in New York City.
Brooklyn is also a hot spot for mold complaints, where renters submitted 311 reports 11,075 last year. That’s 149.1 complaints for every 10,000 renters. Flatbush received the most mold complaints out of any neighborhood last year, and has already had 205 complaints in 2025.
Since 2020, mold complaints have consistently increased across all of the boroughs, except Staten Island. After renters returned to the city post-pandemic, there were more opportunities for tenants to notice and complain about mold. Additionally, as the region witnesses more summer storms and wet conditions, mold has more opportunities to grow.
Mold Complaints, Mapped Out By NYC Neighborhoods
The interactive map below breaks down mold complaints to NYC 311 by neighborhood and highlights the top reported addresses. To fairly rank each neighborhood, we divided the average yearly complaints from 2017 to 2025 by the total number of renter-occupied units. The lighter the shade, the more complaints per 10,000 renter-occupied units. We also included median one-bedroom rents by neighborhood as a reference point for renters.
The map highlights the higher concentration of mold complaints throughout the Bronx and parts of Brooklyn. Renters also frequently complained about mold throughout Upper Manhattan.
The Moldiest Neighborhoods in New York
- Flatbush, Brooklyn: 340 complaints in 2024, 623.6/year
- Concourse-Concourse Village, Bronx: 375 complaints in 2024, 597.7/year
- Harlem (North), Manhattan: 397 complaints in 2024, 591.1/year
- Crown Heights (North), Brooklyn: 341 complaints in 2024, 550.8/year
- Washington Heights, Manhattan: 319 complaints in 2024, 512.5/year
The Mold Problem Is Getting Worse In These Neighborhoods
- Douglaston-Little Neck, Queens: 7 complaints in 2024 (+250%)
- Bath Beach, Brooklyn: 51 complaints in 2024 (+169.4%)
- Gravesend (South), Brooklyn: 67 complaints in 2024 (+157.7%)
- Westchester Square, Bronx: 180 complaints in 2024 (+130.8%)
- Jamaica Hills-Briarwood, Queens: 108 complaints in 2024 (+116%)
Addresses with the Most Mold Complaints in NYC
- 2069 Walton Avenue, Bronx: 151 complaints in 2024, 22 complaints in 2025
- 760 Eldert Lane, Brooklyn: 112 complaints in 2024, 17 complaints in 2025
- 790 Eldert Lane, Brooklyn: 55 times in 2024, 14 complaints in 2025
- 354 Chauncey Street, Brooklyn: 49 complaints in 2024, 20 complaints in 2025
- 20 Richman Plaza, Bronx: 49 complaints in 2024, 9 complaints in 2025
New York City Has Gotten Moldier In Recent Years
The following chart breaks down mold complaints from 2017 through 2025 by month to highlight seasonal trends.
Renters complain more about mold in the later summer through early winter months. During the spring and early summer, complaints decrease. Peak hurricane season, which spans from mid-August to mid-October, can impact mold complaints, as the region receives a higher concentration of rainfall, giving more room for mold to grow. Late summer in New York City is also hot, and apartments without central air conditioning may be more prone to mold. The likelihood of mold increases in humid areas without windows, like the bathroom.
Hurricane Ida’s Long-Lasting Impact
Mold complaints reached their highest level on record in September 2021, when renters flocked back to the city post-pandemic for work and school. However, increased moisture and humidity compounded complaints. On September 1st, Hurricane Ida swept through the city, severely flooding many neighborhoods. In a historic natural disaster, unprecedented amounts of rain fell, displacing cars, flooding basements, and creating opportunities for mold growth. Renters felt the effects of the storm and discovered more mold that month, lasting through the rest of 2021. September 2021 remains the month with the highest number of mold complaints on record.
2024 Was NYC’s Moldiest Year on Record
2024 witnessed the highest volume of mold complaints per RentHop’s record, with 36,178 complaints across the five boroughs. The Bronx, Brooklyn, Manhattan, and Queens received record-setting numbers of complaints. From 2023 through 2024, mold complaints increased across 59% of the city’s neighborhoods. Additionally, 20 neighborhoods received at least 50% more mold complaints in 2024 than in 2023.
While 2024 did not receive as much precipitation and did not have as high of a yearly temperature, the air quality did reach concerning levels. Wildfires in Canada negatively impacted the air quality in New York City, and the city encouraged residents to keep their windows closed, thereby limiting airflow.
2025 Mold Complaints in the Making
So far this year, 2025 has fewer mold complaints than 2024. 2024 had more mold complaints for January through May. While 2025 is on track to witness fewer mold reports compared to previous years, there is still time for conditions to change.
Hurricane season has only just begun, and while the city experienced a cooler spring, summer could heat up. Temperatures reached over 100° for the first time since 2012, potentially indicating a record-hot summer. If precipitation increases as well, more renters could find mold in their apartments.
Renter Self-Advocacy
Mold complaints may continue to increase, partially due to changing renter attitudes and access to online information. New York City offers an online portal to submit mold complaints, and as more renters learn about the ease of submitting complaints, they may be more likely to do so when they would have remained quiet in years past. Renters also post about mold on social media, which informs their peers, also increasing the likelihood of renters submitting complaints.
Furthermore, the average rent in New York City continues to rise. As renters receive renewal notices for higher rents and face an expensive market, they may be less willing to put up with unsafe housing conditions. Renters who received COVID-19 deals for their apartments may no longer have a cheap rent, meaning they will escalate to 311 if their landlord does not respond.
Why Should Renters Care About Mold Complaints?
Mold exposure causes various symptoms, and living in a mold-infested apartment will prolong and intensify the effects. Renters with mold allergies or asthma can suffer more intense reactions to mold. Overall, those living in mold-infested apartments are more likely to suffer from wheezing, red or itchy eyes, a stuffy nose, and skin irritation, according to the Center for Disease Control (CDC). In severe cases, renters can develop fungal infections that require diagnosis and treatment by a medical professional.
To limit the risk of symptoms and infections, renters should avoid living in apartments with mold and promptly report any appearances to their property manager. Renters who plan to move to a neighborhood with high mold complaints should take extra precautions to investigate their apartment’s history of mold.
How to Spot Mold During an Apartment Tour
It’s important that you recognize the signs of mold during apartment showings. Some common signs of mold include:
- Gray, green, yellow, black, or orange patches
- Furry, slimy, or powdery areas
- Musty, earthy, or stale smells
Mold grows more easily in wet and damp places. If the bathroom does not have a window or if the apartment does not have strong ventilation, it is easier for mold to grow. Mold may appear on fabric, wallpaper glue, wood, and other surfaces. Warm temperatures and high humidity increase the likelihood of mold.
If you’re touring an apartment and believe you see mold, ask the agent or person showing the unit for further information. Should they identify mold in the unit, the owner should take proper steps to remove the mold before your move-in date. However, a vacant apartment should not have enough moisture to grow mold, and renters could also consider not leasing the unit if there is already an issue with mold.
What to Do When You Find Mold in Your Apartment?
If you discover mold in your personal apartment or throughout the building, you should contact your landlord or property manager to address the issue. Some mold spots may be safe and easy to clean on your own, but documenting the incident to building owners can help establish a timeline if the problem persists or worsens. Landlords are responsible for properly cleaning mold and improving any situations that continue to increase the presence of mold in the apartment. Your building manager may send someone to come and clean the mold and address the root of the problem, like a leaky pipe.
If your landlord or property manager does not address the mold, call 311 to report the issue or file a complaint online with the Department of Housing Preservation and Development (HPD). HPD will attempt to contact your building manager and potentially send a uniformed Code Enforcement inspector to review the situation and check for any additional violations. They will ticket the building owner for violations. If the owner does not rectify the problem within the designated period of time, you can initiate legal action against the owner in Housing Court.
Questions? Email press@renthop.com
