Most thunderstorms last about 30 minutes and are typically about 15 miles (24 km) in diameter. The two biggest threats associated with most thunderstorms are lightning and flash floods. To understand why thunderstorms occur more often during the warm months requires some understanding of thunderstorm basics. read more
In Summer, particularly late summer in temperate regions, or indeed in very hot humid climates, storms like thunderstorms or hurricanes occur because the heat energy in the atmosphere is released, particularly when reacting with cooler air masses. read more
These apply during Summer, as you would most likely get warm air coupled with high humidity in Summer, not as much as Winter. The high humidity, with rising warm air can easily spark off a thunderstorm. read more
The peak in summer/autumn is due to having all of the necessary ingredients become most fa vorable during this time of year: warm ocean waters (at least 26°C or 80°F), a tropical atmosphere that can quite easily kick off convection (i.e. thunderstorms), low vertical shear in the troposphere, and a substantial amount of large-scale spin available (either through the monsoon trough or easterly waves). read more