The temperatures in epipelagic zone range from as high as 97 degrees Fahrenheit in the Persian Gulf to as low as 28 degrees Fahrenheit near the North Pole. The epipelagic zone is the surface layer of the ocean.
The epipelagic zone receives the majority of the ocean's visible light; therefore, it is the warmest part of the ocean. The varied heating from this zone causes the wide ranges in surface water temperatures, both due to location and seasonal changes. As the wind passes over the water, the heat is distributed down. The area where the differences in sun and wind stop affecting the heat of the ocean marks the beginning of the thermocline transition layer.