Rain

The rain is the ultimate danger to Slugcat. The rain will come approximately 15-20 minutes after slugcat wakes up in the hibernation room. When the rain comes, it will totally flood the underground areas and drop raindrops that are as strong as bullets, so there is simply no way for slugcat to avoid the rain. Slugcat must find a place for hibernation before the rain comes, as hibernating will reset the time, giving you approximately 20 minutes until the rain.

Each day in Rain World is a different length. A symbol in the bottom left of the screen indicates roughly how long is left in the day - the number of "pips" around the symbol shows the time until the rain arrives. This symbol can be seen at any time by viewing the map, and it will also flash up automatically once half the day is gone.