Ask A Scientist General Science Archive

Question:
A third grader would like to know how many tornadoes have landed 
in the United States since 1920?
 pleasant lane

Answer:
According to "It's Raining Frogs and Fishes" by Jerry Dennis,
an average of 850 tornadoes occur in the U.S. each year.  At
that rate, we can estimate that there have been
about 60,000 tornadoes in the U.S. since 1920!  It might also
interest you to know that tornadoes are more common in the
United States than any other country and that the winds inside them
can reach up to 250 miles per hour.
 
As the title of the above-mentioned book implies, there have been
a number of reports of fish and frogs falling from the sky.
One possible explanation for this is that the high winds of
tornadoes over water--often called water spouts--pick up
the frogs and fish and then deposit them on dry land.
 
-Grant