Thunder and Lightning in the Rainy Season Thunder and lightning are two of the most awe-inspiring natural phenomena. They can also be dangerous, so it's important to understand how they work and how to stay safe. What causes thunder and lightning? Lightning is caused by the buildup of electrical charges in clouds. As water droplets in the clouds collide, they rub against each other and create static electricity. The positive charges collect in the upper part of the cloud, while the negative charges collect in the lower part. When the electrical field between the two charges becomes too strong, a lightning bolt forms. The lightning bolt is a sudden discharge of electricity that travels from the cloud to the ground, or from cloud to cloud. The heat from the lightning bolt causes the air around it to expand rapidly, creating a sonic boom that we hear as thunder. Why is thunder and lightning more common in the rainy season? The rainy season is a time of high humidity, which is a key i