Obviously yearly rainfall totals give us a better idea of the degree of drought, but how much variance is typical in yearly rainfall totals? What is the standard deviation on annual rainfall amounts at RDU?Posted — Updated
MIKE MOSS SAYS: Matt, Using data from the current "climate normals" period of 1971-2000 at RDU, the average yearly precipitation there is 43.1 inches, and the standard deviation about that mean is +/- 6.4 inches. So, historically we have seen between 36.7 and 49.5 inches about 67% of the time, and should fall between 30.3 and 55.9 inches about 95% of the time.
Copyright 2023 by Capitol Broadcasting Company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.