It has been raining and thundering around these parts.  It got me thinking.  I wondered how much water was actually falling, so I did a little simple math.

Assuming an area of 10 square miles and 1 inch of rainfall, how much water actually fell?

1 pint = 1 pound
There are 28.88 cubic inches of water in 1 pint.
1 mile = 1760 yards = 5280 feet = 63360 inches
10 square miles = 100 miles = 63,360,000 inches
63,360,000 inches / 28.88 cubic inches per pound = 2,193,905.8 pounds (round that off to 2.194 million pounds)

conclusion in weight:
2000 pounds = 1 ton (U.S.)
2.194 million pounds / 2000 = about 1.1 thousand tons of water.

conclusion in volume:
8 pints = 1 gallon
2.194 million pounds / 8 pints/pounds per gallon = 274,238 gallons of water

Now, rainfall commonly covers areas a lot larger than 10x10 miles and in quantities of more than one inch, but this gives a good feel for it all.