Why do tropical cyclones occur in late summer?​

because that is the time of year when the two most important ingredients needed for their formation

Explanation:

ingredients are warm ocean waters. hope this helps

Tropical cyclones in the Atlantic Basin are most numerous during late summer and early autumn

Explanation:

because that is the time of year when the two most important ingredients needed for their formation — warm ocean waters (80 degrees or higher) and weak vertical wind shear (little change in wind direction and/or speed with height) — are most prevalent. This is also the season with the highest frequency of west-moving weather disturbances in the tropics that eventually develop into hurricanes.