The grass is green, mushrooms are loving life, and it seems like every time we look outside there’s a downpour. This is typical for May — or maybe June — but by late July and into August, this kind of rain turns heads.
Well, it turns forecasters’ heads, at least.
June was actually pretty dry, and we thought at the time we might be dealing with a summer drought. But that couldn’t have been further from the truth. Since the beginning of June, over a foot of rain has fallen in the Washington area from July 1 through Aug. 15, and some spots have seen more rain. That’s more than twice the average.
We entered summer (June through August on the climatological calendar) in a rainfall deficit that had persisted for the whole year before. Short-term drought indicators were up, and talk of a real drought looming this fall was increasing.
Coming into June, Washington was running about 4 inches behind normal for the 2017 tally so far, with five of the six months below normal for precipitation. This was on the heels of a back half of 2016 that was about 7.5 inches below normal.
A paltry June total of 1.13 inches of rain — versus the average 3.78 inches — made things even drier.
Then July happened, and the trend reversed. In fact, more than a half an inch fell on July 1. During the first week it rained so much that a Washington Nationals game had a three-hour rain delay.
Week two it rained again. Week three, a big rain. Finally, the month ended with flooding during a storm that dropped more than five inches of rain in some parts of the D.C. metro region.
The first week of August ended with a deluge. The area picked up another inch or more in the middle of week two. Then it poured again on Tuesday.
All in all, since July 1, we’ve seen eight rain events across the metro area, each spaced about a week apart. Five of those surpassed an inch of rain at Reagan National Airport. One ranked among the all-time great rain events of July.
Through Aug. 15, it all adds up to 12.17 inches of rain in the city since July 1. To put that in perspective, the average for the 30 years ending in 2016 during that period is 5.3 inches.
The period from July 1 through Tuesday ranks as the city’s seventh wettest on record, dating to the 1870s. It was also the seventh rainiest July on record, with a rainfall surplus of about 5.5 inches. The 3.02 inches of rain recorded this month so far is already above the whole month average of 2.93 inches. August is usually the dry month of the warm season.
As seen in the graph above, the last time it was close to this wet over the same period was 2004. In September of that year, Hurricane Ivan came along. We’re again heading into the peak of the Atlantic hurricane season with saturated soil. The upcoming season is historically when we can see big rain events as those systems take swipes at the East Coast and Gulf of Mexico.