In the heat of summer, all sorts of tourists head north to cooler climes. This year, a manatee has joined the crowd, cruising past the nightclubs of Manhattan and continuing north.

The massive animal has been spotted in the Hudson River at least three times in the last week — first off the Chelsea and Harlem sections of Manhattan, then to the north in Sleepy Hollow in Westchester County.

“It was gigantic,” said Randy Shull, who said he spotted the unusual visitor Sunday afternoon while boating at Kingsland Point Park in Sleepy Hollow. “When we saw it surface, its back was just mammoth.”

Last month, trackers saw the manatee as it swam north, first near Delaware, then Maryland, then New Jersey. By Saturday, it was seen in Manhattan.