New York’s heaviest downpour on record dumped a summer’s worth of rain on parts of Long Island in a matter of hours Wednesday, swamping highways before drivers could escape, flooding basements and causing at least one death.

The 13.26 inches recorded at the MacArthur Airport in Ronkonkoma during the morning was more than the area’s normal combined total for June, July and August of 11.75 inches. It smashed the previous state record for 24-hour rainfall of 11.6 inches near the Catskills town of Tannersville during Tropical Storm Irene three years ago.

“What happened today was unprecedented,” Suffolk County Executive Steve Bellone told reporters Wednesday outside the North Babylon firehouse where dozens of stranded drivers were brought for shelter during the height of the storm.

Volunteer firefighters in communities across Long Island used trucks and equipment usually used to fight brush fires to rescue stranded drivers. The trucks stand high off the ground and can maneuver through several feet of water.

On the Southern State Parkway in North Babylon, firefighters encountered about 50 vehicles either stuck in the rising waters or pulled off to an elevated apron on the side of the highway.

“We had occupants climbing out of windows because they couldn’t open their doors,” said Lt. Timothy Harrington, the first firefighter on the scene. “Some of the water was over the vehicles’ roofs. I’ve never seen anything like this before.”

James Piano, of Islip Terrace, was rescued by firefighters in North Babylon after his truck was swamped with waist-high water.

“That little Miata over there was floating in the middle lane, literally floating,” Piano said.

No injuries were reported among the stranded drivers, but officials said one person died when an SUV driving slowly during the height of the downpour was hit by a tractor-trailer carrying waste oil on the Long Island Expressway near Dix Hills.

Suffolk County Police Chief James Burke said the person who died was in the SUV.

No charges were immediately filed, but police said the weather-related crash was still under investigation.

By midmorning, the water subsided there and traffic began moving again along a road surface coated with a slippery-looking film of oil, dirt and grass.

Officials reported few power outages resulting from the storm.

Some south shore Long Island communities slammed by Superstorm Sandy nearly two years ago were experiencing certain flashbacks as roads were closed and some homeowners were dealing with flooded basements.

Gerard Kapetanakis said there was about four inches of rain in his basement in Lindenhurst. “There was so much water there was no place for it to go,” said the construction worker.

Laura Cutuli, a nurse, never made it to her job Wednesday at New York Presbyterian Hospital in New York City.

Her stranded car was filling with water, so she had rolled down her windows to “rescue myself if I had to.” Instead, firefighters aided her and other motorists.

“We were standing in the water,” Cutuli said. She said it was cold, dark and “just surreal.”

The storm dumped varying amounts of rain as it passed over the Northeast.

New York City ranged from under an inch in Central Park to over 3 inches at Kennedy Airport.

But parts of New Jersey also got more than 7 inches. Several homes were evacuated in Millville, New Jersey, because of flooding.

Baltimore got 6.3 inches, its highest rain total since 1933 and the second-highest since measurements were first taken in 1871.

In Rhode Island on Wednesday, manhole covers were swept off by water that filled the streets in Providence.

The same system dumped rain on Michigan earlier in the week, causing flooding that shut down most of the Detroit-area expressway system. Authorities cleared mud, debris and abandoned vehicles and finally reopened all freeways Wednesday.