April was a little warm and a lot wet
Posted May 4, 2015
Updated March 31, 2016
I suspect I'm not the only one who perceived April this year to be on the gray and chilly side for a spring month. Reviewing the numbers now that they're all in, though, shows that while the gray and wet part were pretty much on target, the cool weather came in short enough bursts that we actually averaged out with temperatures a little on the warm side of normal.
The first graph you see here shows that our mean temperature for the month at RDU was 61.5 degrees, which was 1.3 degrees above normal. In 129 years of data for Raleigh, this was tied for the 16th warmest value, although due to some other ties there are 28 years that have been warmer, including of course the warmest average of 63.6, which has occurred five times, most recently in 2011.
In 1907, the area must have been absurdly cool to come in with a mean value of 52.1 degrees!
One reason April 2015 probably didn't seem so much like a warmer-than-average month was that the maximum temperatures for the month averaged 72.4, only a tenth of a degree above normal, while lows averaged 50.6, topping normal by a sizable 2.6 degrees. We did have two chilly days with temperatures that failed to climb out of the 50s in the afternoon, but there were also five days that reached or topped 80. We didn't have any days in the month with highs at 90 or above or with lows at or below freezing.
On the precipitation side, we see in the second graph that total rainfall at RDU for April was 5.3 inches, far above the normal of 2.9 but also a good deal shy of the wettest on record, when 8 inches fell in 1895. This year ranks as the 13th wettest April in the record book, which stretches back to 1887.
We had measurable rain on 12 days during the month, compared to a normal of nine days, and on five of those days we received a half-inch or more soaking.
The rainy month came along with some notable cloud cover, as you might expect, and we ended up with daytime sky cover that worked out to four days with "fair" skies (the long-term average is 10), 12 "partly cloudy" days (average is 9) and 14 "cloudy" days, compared to an average of 11.
We've ramped up the sunshine and the temperatures some as we've headed through the first days of May, and it appears we'll reach or top 80 for much of this first full week of the new month, although there are some question marks for late in the week due to the uncertain (as this is written) future path and speed of a low pressure area that will likely form off the southeast coast by midweek, and potentially take on some tropical characteristics as it evolves.