While not as hot at the record-shattering 2010 (two degrees cooler), summer got off to a historically steamy start in Washington, D.C. Averaging more than four degrees above average, June 2011 tied with 1943 as the third hottest on record.
In recent years, Junes have trended hot. The blog Capital Climate noted: “Two out of the top 3 hottest Junes, and 3 of the top 6, have been in the last 4 years (2008, 2010, and 2011). Only 1 of the top 5 [hottest years] has occurred prior to 1981.”
D.C.’s hottest temperature was that blistering day on June 9 when the mercury soared to a record-tying 102. It not only matched the daily record from 1874, but also the hottest monthly temperature, and earliest reading in the season so hot. On the same date, a record high minimum temperature of 79 (beating the previous 2008 reading by two degrees) was set. Additional record highs were set on June 1 (98) and 8 (99). And another record high minimum occurred on June 1 (76).
We had 10 days at or above 90 during the month compared to the 1981-2010 average of 7.1 days. Last year, we had a brutal 18 days at or above that 90-degree threshold..
Our coolest high temperature of the month occurred on June 15, a relatively cool 79.
Precipitation at National Airport was only 1.68”, which is not as dry as our driest on record (0.86” way back in 1940). It actually rained at the airport on 18 of the 30 days of the past month. But most days only produced a trace to a hundredth of an inch. Our one-day biggest rain total was a much-needed 0.83” on June 16.
The precipitation pattern type over North America in June was typical of one seen during and in the wake of a Pacific La Nina pattern. These situations tend to favor a hot and dry South, which can frequently edge up the East Coast as well. The Federal Government’s Drought Monitor, below, shows this pattern type well.
This issue may become a bigger story for the balance of summer as dry soil conditions can enhance heat waves and, of course, create lots of other problems (farm woes, water shortages, and, of course, fire danger). Despite some early July storms, we are still running about three inches below normal since January 1
The National Weather Service publishes nice monthly assessments usually within a week of the close of each month (should be available shortly):
You can click on your closest airport location here:
Historical Washington, DC data provided by NOAA and Speedwell Weather.
CWG’s Jason Samenow contributed to this post.