New Yorkers were warned to stay out of basements and seek higher ground Monday as heavy storms threatened flooding in low-lying areas of NYC for the second time in 24 hours.
The National Weather Service issued a flash flood warning for sections of Brooklyn, Queens and Nassau County Monday afternoon, with heavy rains of 1 to 2 inches expected until 1:30 p.m.
The city’s sewage system has the capacity to clear only 1.75 inches of rain per hour.

Theodore Parisienne / New York Daily News
People walk in the rain in the Bronx on Monday. (Theodore Parisienne / New York Daily News)
“Don’t drive/walk where water covers roadway,” the NYC Office of Emergency Management said in a tweet. “Move to higher ground, or if in a basement, move to a higher floor.”
As of 11 a.m., Brooklyn had received the heaviest rainfall since a series of storms hit NYC last night, NYCEM reporting 2.80 inches of rain recorded so far in Sheepshead Bay, and 2.14 inches reported at Brooklyn College.
Queens has recorded 1.94 inches in Ozone Park and 1.83 inches in Howard Beach.

Theodore Parisienne / New York Daily News
A person rides a bicycle in the rain in the Bronx on Monday. (Theodore Parisienne / New York Daily News)
The warnings came after Mayor Mamdani asked New Yorkers to limit travel and prepare for possible flooding Monday morning ahead of the first wave of thunderstorms overnight.
“We are asking every New Yorker to stay safe, and so, if you are able, we ask that you do not travel tomorrow morning,” Mamdani said in a social post Sunday night. “If you live in a basement apartment, start to plan. If you see water rising around you, move to higher ground.”
“If you are in any kind of danger, call 911,” he added.
Subway service remained largely unaffected Monday afternoon, though service on the above-ground Staten Island Railway was delayed as MTA crews cleared water from the tracks.