Why is this the answer?

The answer is volcano because this amazing riddle describes what happens when a giant, fiery mountain explodes. Let's think about the clues like they are pieces of a puzzle, and each piece tells us about a different part of the eruption. The first clue is: "My thunder comes before the lightning." When a volcano is about to erupt, a lot of intense pressure builds up deep underground. You do not see fire or bright light right away. Instead, you hear a very deep, loud rumbling noise and shaking coming from inside the mountain as the hot magma pushes up. This loud, shaky sound is the volcano's "thunder." The "lightning" is the bright, glowing red and orange lava that you finally see once the volcano bursts open at the top. The ground shaking and sound waves are often felt and heard first, so the thunder is experienced before the bright lightning of the fiery eruption is actually seen. The next clue is: "My lightning comes before the clouds." The "lightning" we know is the bright light and fire. The "clouds" are the huge, towering columns of dark smoke and ash, called the eruption plume, that shoot very high into the sky from the volcano's crater. In a big eruption, the first bright flash of fire from the lava often appears very quickly. This bright glow and fiery display typically break through the top of the volcano before the massive, dark plume of smoke and ash has fully formed and spread out in the atmosphere, looking like a huge cloud. Finally, the riddle says: "My rain dries all the land it touches." When a volcano has "rain," it is not water like in a normal storm! Its rain is made of super hot, melted rock called lava, or sometimes hot chunks of ash and pumice. When this incredibly hot "rain" or flow touches the green, living land, it is so hot that it instantly burns, scorches, and covers everything. It makes the land completely barren, or "dry," meaning it destroys all the plant life and leaves the ground as a desert of rock, so nothing can grow there for a very long time. This is a very clever and dramatic way to describe the powerful and destructive nature of a volcanic eruption.