A friend passed me in the stairwell yesterday and asked how unusual is it to have such a wet summer. Lucky him! I had just looked at our climate data from Raleigh-Durham International Airport's records the day before, so I had a pretty accurate answer. We were about 10 inches above normal for the year in rainfall, but nearly exactly in the same place compared to last year. Then, it rained at the airport last night.
Keep in mind that "normal" as defined for the purpose of climatology is based on a 30-year average. Our current 30-year range is 1981 to 2010, so our wetter than normal stance at this time last year does not figure into our average yet.
Since January 1st, 38.33 inches of precipitation (rain, sleet, snow, ice) have been recorded at RDU. The 30-year average for January 1st through August 20th is 27.91 inches. We currently stand 10.42 inches above normal in precipitation for the year. One year ago today, we were at 37.46 inches. At this point, we are pacing ahead of last year.
Does all of this data mean that we'll end the year much wetter than normal? It is possible. A quick glance at the Climate Prediction Center's September through November outlook shows that we have "equal chances" of average, below average, or above average rainfall for the next three months, meaning that there is nothing in the models to indicate a strong trend one way or the other.
Either way, a cooler and wetter than normal summer seems to be appreciated by everyone who enjoys a nice, green lawn. Although with a forecast high in the mid-90s and a heat index near 100 degrees today, it will be easy to forget that summer is almost over.