WRAL WeatherCenter Blog

Hi! I see that in the drought coverage, you show what rain we've had as compared to what we normally have had since Jan. 2007. What does the comparison look like if we compare for the last 3, or 5 years - or maybe even for the last decade?

Posted April 20, 2008 1:39 p.m. EDT

MIKE MOSS SAYS:      CJ (Kids, too!),     For the three year period 2005, 2006 and 2007, rainfall at RDU totaled up to 127.04 inches, compared to a normal for the three-year period of 129.15. So, the anomaly over that stretch of time was 2.11 inches below normal. You can find a list of yearly rainfall totals for stations in North Carolina at


Just click on the station you want and then look down the left hand side under "Precipitation" for the "Monthly Totals" link. Note that data on the site is not complete for 2007 yet, but RDU received 35.81 inches of rain for that year. You can use the tables to calculate 5-year, 10-year, etc anomalies, some of which will be deficits and some surpluses. Of course, once a prolonged stretch of below-normal rainfall has combined with evaporation and water usage patterns to lower streamflows, reservoirs and groundwater levels for a while, any previous surplus from long ago isn't really relevant anymore, and one could say the same about a long-ago dry period once a prolonged period of normal or above-normal rainfall results in saturated soils, full reservoirs, and relatively steady streamflows at near normal values.