Rain

The rain is an ever present danger to slugcat and the other terrestrial creatures of Rain World. Each occurrence of rain begins with a shaking of the screen and a deep rumbling noise, as well as a scattering of all creatures into their shelters. The rain will at first obscure vision and hamper movement, and either drown or crush unlucky creatures caught in the downpour. Slugcat must find a place for hibernation before the rain comes, in order to sleep until the next cycle.

Variation in rains
The coming of rain will have different effects based on which screen the character finds itself on. In outdoor regions the rain will directly appear to impact the slugcat's movement, concentrating in areas directly beneath the sky. Here, the rain will kill the slugcat faster depending on the strength of the rain it is standing in. In indoor regions the rain will cause a hurried flooding of the interior with water. Here the only threat is eventually drowning beneath the surface of water. In other areas, including Five Pebbles, the upper limits of The Wall, and any shelter, the rain has no effect.

In the minute before the end of the cycle, the background will become darker. 30 seconds before the end of a cycle, vibrations of the oncoming rain can be felt and heard. From here, the rain will most commonly increase steadily in strength from a drizzle to a lethal downpour over 45 seconds after the last pip. Occasionally, however, the rain will have a false start, in which case the vibrations and rain will stop shortly after the end of the cycle. This break will last about 10 seconds, ending when loud individual droplets are heard. Following this intermission, the rain immediately jumps to its full strength and all underground regions will begin flooding.

Cycles
Each cycle in Rain World has a random duration, visible in the bottom left corner surrounding the karma symbol. The "pips" each represent 30 seconds, and each cycle can last a maximum of 26 pips with an extra 20 seconds not shown in the timer (13 minutes and 20 seconds). The minimum cycle length depends on difficulty - Survivor and Hunter have a minimum cycle length of 13 pips (6 minutes and 40 seconds), while Monk has a higher minimum cycle length of 18 pips (9 minutes). Telltale signs of the rains can be felt as early as a minute before the end of a cycle, rains come shortly thereafter. The cycle timer can be seen at any time by viewing the map, and it will flash up automatically once half the cycle is gone.

Tips

 * It is possible to survive longer during the rains in flooding underground rooms. Bubble weed can be used to prolong breath underwater while searching for shelter.