New York City has confirmed 18 deaths linked to a prolonged period of extreme cold, city officials said, as temperatures are expected to gradually rise this week.

Since late January, the city has endured a historic cold snap, with 13 consecutive days at or below freezing (0°C / 32°F), marking one of the longest stretches of sub-zero weather in New York in more than 60 years. Over the weekend, an additional death occurred outdoors, bringing the total fatalities to 18, Mayor Zohran Mamdani said Monday.

"Each life lost is a tragedy," Mamdani emphasized, urging residents to exercise caution and remain indoors whenever possible. He also called on New Yorkers to check in on vulnerable neighbors and family members during the ongoing cold spell.

Following the declaration of a Code Blue emergency on January 19, which eased intake policies for homeless shelters, city officials have placed approximately 1,400 individuals into temporary shelters. The city also added 64 hotel rooms for residents in need and deployed at least 150 outreach workers to assist those living on the streets. Despite these measures, the extreme cold continues to pose a significant risk to those without adequate shelter or heating.

Of the 18 deaths reported, at least 10 were individuals found outdoors. The circumstances of the remaining fatalities are still under investigation, highlighting the severe impact of extended exposure to freezing temperatures.

The National Weather Service (NWS) warns that while temperatures are expected to rise slightly, they will remain below the seasonal average. Highs for the week are forecast near freezing, compared to normal highs around 4°C (39°F) for this time of year. Dangerous wind chills associated with the Arctic air mass have increased the risk of frostbite, hypothermia, and other cold-related illnesses.

Residents are also being cautioned about secondary hazards caused by the extreme weather. Melting snow and ice may fall from rooftops without warning, while streets and sidewalks can refreeze overnight, creating slippery and treacherous conditions. City agencies continue to monitor infrastructure concerns, including icy roads, delayed public transportation, and power outages affecting heating systems.

Experts note that prolonged exposure to such cold can have serious health consequences, particularly for the elderly, children, and individuals with pre-existing medical conditions. Cold weather can exacerbate cardiovascular and respiratory issues and increase the risk of accidents due to slips and falls.

City officials are urging residents to dress in layers, limit time outdoors, and seek emergency assistance if needed. Public shelters, warming centers, and local outreach programs remain operational to provide aid to those at risk.

"This extreme cold event has tested our city's resilience," Mamdani said. "We are committed to protecting all New Yorkers and ensuring that vulnerable populations receive the support they need during this challenging period."