Water warmth depends on personal preference, but some measures consider about 63 to 68 degrees, for example, to be ideal outdoor swimming weather. On the Florida side of the Gulf Coast, the water is slightly cooler than this in the winter, but many people, especially tourists, brave the slight chill on a hot sunny day. The touristy areas along the Gulf Shore feature very warm water ideal for swimming in the summer, with temperatures ranging from the low to high 80s from May to October in the Eastern Gulf and from June to September in most of the Western Gulf.
A Mediterranean-type sea, the Gulf of Mexico is located in the southeastern section of North America. Five U.S. states -- Texas, Louisiana, Mississippi, Alabama and Florida -- form the northern border. The gulf also touches Cuba in the southeast and five Mexican states Yucatan, Tabasco, Tamaulipas, Veracruz, and Campeche to the west. Altogether, it has a surface area of more than 900,000 square miles.
Water temperatures in the Gulf of Mexico vary based on season and location. During the summer months - June to September - water temperatures tend to be in the mid-80s, although high 70s are not unusual. Sabine Pass, Texas, in the Western Gulf, has the lowest temperatures: During the winter, temperatures drop as low as 32 and only rise to the mid-60s for much of the summer. Much of the Florida coast, in the Eastern Gulf, has temperatures in the mid-60s even in the winter, rising to the very high 80s in the summer.
Depth Impact on Temperature
Much of the Gulf of Mexico has fairly shallow waters -- almost 40 percent is less than 65 feet deep -- which allows it to heat quite thoroughly, unlike bigger oceans which contain cool water underneath. Water closer to the shore and these shallow areas will be much warmer than water in the deeper seas.
Because the gulf waters stay warm into November, the potential for hurricane development exists yearly through the end of the month. The Atlantic hurricane season is June 1 to November 30 annually. The hurricane-temperature threshold is about 82 degrees.