An IWorld object represents the world the player is currently in.

It might be required for you to import the package if you encounter any issues, so better be safe than sorry and add the import.
import mods.contenttweaker.World;

ZenMethod	ZenGetter	Rückgabetyp	Beschreibung
ZenMethod isRemote()	ZenGetter remote	Rückgabetyp boolean	Beschreibung True if the world is a "slave" client; changes will not be saved or propagated from this world. For example, server worlds have this set to false, client worlds have this set to true.
ZenMethod isRaining()	ZenGetter raining	Rückgabetyp boolean	Beschreibung Returns true if it is currently raining
ZenMethod isThundering()	ZenGetter thundering	Rückgabetyp boolean	Beschreibung Returns true if it is currently thundering
ZenMethod getMoonPhase()	ZenGetter moonPhase	Rückgabetyp int	Beschreibung Returns the current moon phase
ZenMethod isDayTime()	ZenGetter dayTime	Rückgabetyp boolean	Beschreibung Checks if it is daytime
ZenMethod getWorldTime()	ZenGetter time	Rückgabetyp long	Beschreibung Returns the world's time
ZenMethod getDimension()	ZenGetter dimension	Rückgabetyp int	Beschreibung Returns the world's dimension
ZenMethod isSurfaceWorld()	ZenGetter surfaceWorld	Rückgabetyp boolean	Beschreibung Returns whether you are in a surface world or not
ZenMethod getDimensionType()	ZenGetter dimensionType	Rückgabetyp String	Beschreibung Returns the dimension's type name
ZenMethod getRandom()	ZenGetter random	Rückgabetyp CTRandom	Beschreibung Returns the world's random number generator

• IBiome getBiome(IBlockPos blockPos);
• boolean setBlockState(ICTBlockState blockState, IBlockPos blockPos);
• ICTBlockState getBlockState(IBlockPos blockPos);