Why the warmest sea surface temperatures do not occur until late summer and early fall?

The warmest sea surface temperatures typically occur in late summer and early fall due to the lag between solar heating and the temperature of the ocean. Throughout the summer, the sun’s energy continuously warms the water, but it takes time for the ocean to absorb and retain that heat. Additionally, factors such as wind patterns, ocean currents, and thermal inertia contribute to this delayed peak in temperature, as the ocean acts as a large heat reservoir. As the sun's intensity begins to decrease in the fall, the accumulated heat leads to the warmest surface temperatures before cooling begins.