Rain



Rain is a feature activated by pressing F5 in-game in Classic. Rain can also fall on Multiplayer, but cannot be seen by other players. It will only fall where the sky isn't blocked, and currently has no effect on gameplay. Rain is a single moving sprite. When it falls on a block it makes a splashing effect. To improve frame rate, rain isn't replicated all throughout a map. It is instead one sprite on all sides of the player. When the player goes inside and far away from the falling rain it disappears but reappears when you move close to outside again. Water does not stop rain like a solid block. Instead, it falls through as if there was air. The same applies to lava and small plants.

Rain in Beta
Notch announced that rain, along with falling snow will be added in Beta 1.5. The rain will water crops, cause snow and ice to accumulate, make wolves wet, put out fires (including mobs on fire ) But will not put out Netherack fire, increase the chances of catching fish and possibly fill up small holes with water. During rain, light level will be one level darker and you won't be able to see the moon or sun. Rain will be temporary and global and thunder is also confirmed. Notch confirmed that thunderstorms will reduce the light level low enough to spawn monsters. Notch has also suggested that lightning that directly strikes a pig will transform it into a Zombie Pigman.