Heat is required for initiating thunder clouds. It makes sense that the frequency of lighting is higher over land because the solid surface of the earth absorbs sunlight and heats up more quickly than water. This results in stronger convection and greater atmospheric instability, which further gives rise to the formation of thunder and lightning producing storms.
A member of NASA’s Global Hydrology and Climate Center’s lightning team, Daniel Cecil, has revealed some regional trends. For instance, a large number of flashes occur during the pre-monsoon month of May in the Brahmaputra Valley of East India. This could be attributed to unstable heating and weather patterns at that point of time.
Tropics are the most favourable areas because the surplus energy over tropics gives rise to conventions and forms thunder clouds. Studies carried out through ages have shown that lightning likes Florida and the Himalayas. It loves central Africa and avoids the north and south poles. Most parts of Central Africa and Northwestern South America, lying near the tropics, witness large amounts of lightning throughout the year.
Image credit- Chan Pak Kei