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Dear Tom,

Does the water equivalent of snow count as part of our annual rainfall total, so that abundant snowfall could make up for a drier rainy season?

Karen Maurer,
Olympia Fields

Dear Karen,

It certainly does. The annual precipitation total is arrived by summing the daily amounts of the water equivalent of all precipitation that has fallen. When precipitation falls as rain the amount is read directly from the official rain gauge and recorded in hundredths of an inch. The smallest amount of measurable precipitation is 0.01 inch with lesser amounts recorded as a trace. When the precipitation falls as snow, the snow is collected in the rain gauge, melted and measured as if it fell as rain. Typically an inch of snow yields about 0.10 inches of liquid equivalent, but that can vary depending upon the temperature during the snowfall.