What causes lightning to strike?

Lightning strikes when electrical charges in a thundercloud create a strong imbalance between the cloud and the ground or between different parts of the cloud. As the imbalance grows, an electrical discharge occurs, creating a lightning bolt. The path of least resistance, such as a tall object or a conductive material, attracts the lightning. The intense heat from lightning can reach up to 30,000 Kelvin, causing the surrounding air to expand rapidly, resulting in the thunder we hear.