Rain

Rain occurs randomly and affects all surface biomes for its duration. Each Rain event begins at a random time and lasts for 24 in-game hours (24 real-world minutes), spanning both day and night portions. When a player is in a Snow Biome during Rain, it appears as a Blizzard, causing snowfall volume to increase.

Rain is primarily an aesthetic Surface effect: It displays Rain/Blizzard graphics, darkened ambient sun/moon light, and altered music. There are however some functional effects.

Rain does not actually produce new Water tiles, nor cause existing Water levels to rise, but it does spawn some unique enemies or enemy variants, and certain Critters behave differently. Some comical effects include Zombies wearing rain coats; Slimes carrying umbrellas; and Goldfish walking upright on land, using their tail fins to casually shuffle about (swimming goldfish will exit water and walk, and walking goldfish will also spawn anew on land).

Other effects include:
 * There is a +20% Fishing Power bonus in all liquid bodies during Rain.
 * Waterleaf blooms.
 * Worms spawn frequently in Forest biomes.
 * NPCs remain in their Houses, as if it were night.
 * If Rain coincides with a Blood Moon, Rain will appear to be red-colored.

See below for a complete list of unique Rain spawns, including Hardmode spawns.