Minecraft wiki entry for Thunderstorm_survival, associated text: If you decide to go out during a thunderstorm, be prepared to fight monsters. Thunderstorms come without warning and, due to the low light level, monsters will spawn. If you are not ready, retreat to your house as quickly as possible and wait it out. If you are stuck outside accidentally, either make an emergency shelter (dig down three blocks, jump in and place dirt over your head or a similar design) or just try to fight the monsters and avoid lightning as best as you can.