Why is thunder so dang loud?

Thunder is a shock wave created when lightning rapidly heats the surrounding air. Its loudness and character vary with distance, terrain, atmospheric conditions, and the type of lightning involved. Because audible thunder means lightning is close enough to be dangerous, people should immediately seek shelter indoors.

雷声是闪电迅速加热周围空气时产生的冲击波。雷声的音量和特点会因距离、地形、大气条件以及闪电类型而变化。只要能听到雷声，就意味着闪电已近到可能造成危险，因此人们应立即进入室内躲避。