By 9 p.m., 7.7 inches of rain had fallen at Kennedy Airport.
It was the most recorded there in a single day since the National Weather Service began keeping records 116 years ago.
The heavy tropical rain is expected to continue Monday, and a flash flood warning is in effect until 9 p.m.
The normal rainfall for all of August in New York is 4 inches - which means the city was socked with two months worth of rain in a single day.
"This is what you would expect in a major hurricane," said Steve Wistar, senior meteorologist at AccuWeather.
Kennedy Airport's old one-day rainfall record, 6.3 inches, set on June 30, 1984, fell by noon.
Central Park, where the city's official rainfall total is recorded, saw 5.8 inches by 10:45 p.m., making it the fifth-wettest day of all time there.
© Stephen Barcelo / News DailyA car takes on water in parking lot at the Target in Lindenhurst.
In the subways, water flooded into tunnels, knocking out parts of seven lines in the morning. By evening, the Metropolitan Transportation Authority said, things were under control.
On Staten Island, firefighters rescued two construction workers who got trapped in a stalled elevator rapidly filling with water.
"We thought we were dead," said one of the rescued men, Ed Tyler, 26, of Milltown, N.J. "I literally thought I was going to die."
Tyler and Wendell Amaker, 48, of Roselle, N.J., were using the elevator to move material in a hotel being turned into senior housing. When the doors stopped opening, they rode down to the basement to see if they could get out - not knowing the basement had flooded.
"We felt it hit the water," Tyler said. "Immediately, the water started rushing in."
The water rose past their waists as they held a cell phone through a ceiling hatch to get a strong enough signal to call 911.
One firefighter went to the roof and shut down power to the elevator while the rest of the team opened the door to the shaft with a universal key.
"They were happy to see us," said Capt. James Melvin of Ladder 86. "The water was going up, down, up some more."
The firefighters lowered a narrow ladder through the ceiling hatch and bent a metal support beam that was blocking the exit.
The men were dirty from the filthy water, but uninjured.
© Nicholas Fevelo / News DailyStaten Island was hit hard by the record rainfall on Sunday.
the snow equivalent works something like this:
Quote " How do you convert snow into rainfall amounts?
Since precipitation is generally measured in inches of liquid water and not in snowfall amounts, snow is usually converted into inches of water by dividing by 10. Thus, ten inches of snow is equivalent to one inch of rain.
Light and loose snow takes more than 10 inches to make an inch of water but dense and slushy snow takes less."
With multiple variations to consider, nevertheless, NYC could have received, oh say +/- 8.3 ft in a day or just shy of 3 meters.
That amount would in itself be frightening, unless however your sitting at a ski hill. Sustained precipitation like this in just a few days would be paralyzing and 10 inches in a day might be light in the future.
Just a thought.