How does a thunderstorm occur?

Accumulation of moisture in the atmosphere causes a thunderstorm. This occurs mostly in summer when the sun is hot and keeps soaking up water from the ground and water bodies. The moist air rises and forms small clouds that pile up gradually to form huge cauliflower-shaped clouds as high as 10 km. Inside the clouds, large water drops and ice crystals form due to extreme cold conditions. These remain afloat, being supported by powerful winds. When they collide and rub against one another, an electrical voltage is produced between the upper and lower layers of clouds. This voltage, once sufficiently high, is discharged in the form of lightning.