Does hot water have more density than cold water?

Cold water has greater density than hot because its water molecules are more sluggish; vibrations and movements are slower and less energetic. The molecules bounce and jostle each other less, so more can fit together in a smaller space. read more

Cold water is always more dense than warm water; the density change amounts to about 4 tenths of one percent between near-freezing and 30 degrees Celsius (86 degrees Fahrenheit). Although small, the difference allows warm water to "float" on top of cold water, a phenomenon that occurs every day in the world's oceans. read more