September ends a little cool and dry
Posted October 1, 2013
We wrapped up the month of September with a beautiful Monday, and it brought a close to a month that ran a little on the short side of normal both in terms of temperature and precipitation.
Temperatures for the month at RDU are shown in the graph above, provided by the Raleigh NWS office. The light green band in the background is the normal range for each day, and the dark blue bars show the observed ranges from low to high. Overall, we ran a little on the warm side of normal for the first half or so of the month and then trended a bit the opposite way afterward. In the end, we averaged a high of 81.0 degrees, with an average low of 60.4, and the mean temperature for the month was 70.7 degrees, which is about 7-tenths of a degree below normal. Our coolest September averaged 67.0 degrees in 1963, while the warmest was 77.3 in 2010.
We closed the month more significantly on the low side of normal for rainfall at the airport, with 2.91 inches, compared to a normal of 4.36 inches for the month. Historically, we've had as little as .23 inches of rain for September in 1985, while the wettest September at RDU brought a whopping 21.79 inches in 1999 (can you say "Dennis and Floyd?")
We've entered into quite a dry pattern here recently, with no measurable rain at RDU since .43 inches fell on September 22nd. Right now it appears we may not see any more measurable rain until around next Monday, Oct 7th. If that forecast checks out, it will end a 14-day stretch with no measurable rain. While that's a lengthy period, it doesn't remotely approach our record, which was a 38-day period from Sep 27 through Nov 3 in 2000!