Minecraft wiki entry for Thunderstorm, associated text: Lightning strikes within a radius of 128 blocks (Java Edition) or 64 blocks (Bedrock Edition) of a lightning rod are redirected to the rod, emitting a Redstone signal. This can be used to prevent flammable structures from being struck by lightning, or intentionally direct lightning toward or away from mobs. During a thunderstorm, they emit spark-like particles, even in biomes where lightning doesn't strike.