Do meteorologists have specific definitions for drizzle, light rain, steady rain, heavy rain, downpour?
— Rick Steffen, Arlington Heights
Rain: Precipitation in the form of liquid water drops that have diameters greater than 0.5 millimeter; if less than 0.5 millimeter, it is drizzle. Rain and drizzle are the only forms of liquid precipitation. Rain is classified as light, meaning rain falling at a rate between a trace and 0.10 inch per hour; moderate, 0.11 to 0.30 inch per hour; heavy, more than 0.30 inch per hour. Drizzle is classified as light, falling at a rate from a trace to 0.01 inch per hour; moderate, 0.01 to 0.02 inch per hour; heavy, greater than 0.02 inch per hour. Other terms such as steady rain and downpour are informal and do not carry meteorological definitions. Showers of precipitation are characterized by the suddenness with which they start and stop, and by rapid changes in intensity.