Heated air rises over the land and is replaced by cool, humid air that sweeps inland and, in turn, is heated and rises. With the ascent of humid air, water vapor condenses into clouds and rainfall develops. By autumn, the land cools more than the sea surface and prevailing winds reverse direction, bringing the rainy season to an end. Monsoons have their greatest impact over portions of Africa and Asia, where 2 billion people depend on monsoon rains for their water supply. 366 inches in July 1861.
Nations depend on the monsoon for their very survival.
When a monsoon bypassed parts of China in 1877, it resulted in crop failures and claimed between 10 million and 13 million lives. Lightning Lightning occurs when electricity travels between areas of opposite electrical charge in clouds, or from a cloud to the ground. One theory postulates the collision of raindrops and hailstones in a cloud leaves them electrically charged, with polarity determined by particle size. The larger, and thus heavier, particles carry a negative charge as they sift to the cloud base, while the smaller, lighter pieces remain positively charged at the top. Another theory holds that updrafts carry positive charges near the ground upward, while downdrafts carry negative charges from the upper air downward.