King mackerel can usually be caught by offshore fishermen in the peak fall season of late September and October. They typically weigh between 15 and 20 pounds, but king mackerel as large as 40 pounds have been reported. King mackerel are found in the Atlantic Ocean from Massachusetts to Brazil, including the Caribbean and Gulf of Mexico. They are a "coastal pelagic" species, meaning they live in the open waters near the coast. They live in water 115 to almost 600 feet deep. King mackerel prefer warm waters, and seldom enter waters below 68 degrees Fahreneheit. They migrate with seasonal changes in water temperature and with changes in food availability. Swimming in large schools, they migrate to the northern part of their range in the summer and to the southern part in the winter.