Water temperature affects the rate at which sugar dissolves. Sugar dissolves faster in warmer water than it does in cooler water. Two things are required for a substance to dissolve and create a solution: the substance itself, or the solute, and the substance it is dissolving into, or the solvent.
One of the factors that increases or decreases the rate at which a substance, such as sugar, dissolves is the temperature of the solvent. For sugar, it dissolves faster at warmer temperatures. This happens because heat increases the molecular action in sugar, and it allows sugar crystals to break down more rapidly.