How Much Water Is There In An Inch Of Snow?
On average, 10 inches (25 centimeters) of snow is equal to inch (2.5 centimeters) of water. Heavy, wet snow may contain as much as 16 percent meltwater by volume. A dry, powdery snow may be as little as1/13meltwater by volume.
Sources: Ahrens, C. Donald. Meteorology Today: An Introduction to Weather, Climate, and the Environment, 5th ed., p. 212; Mineral Information Service, vol. 23 (September 1970), p. 189.