90 degree days in Washington, D.C.: Monthly and seasonal averages, current year stats, and the historical record

This post has graduated to the Capital Weather Gang. I have personally followed 90-degree days for as long as I can remember, so I may figure out some in the weeds things to do here. For now, I will try to stay relatively current on the 2011 count/compare to avg. Please note I have removed a yearly comparison and raw odds graphic from this page which will no longer be updated here.

How’s 2011 doing for 90-degree days in D.C.? As of the 2nd of August, there have been 40 total days 90+ at Washington, D.C., including an all-time monthly record of 25 in July. The highest temperature so far is 104 on July 29. The 102 reading from June 9th tied for the hottest June temperature on record. 102 also occurred on July 22 and 23, and the reading for the 23rd was a record for the day. August 1 reached 100, becoming the 5th of the year.

90F+ averages over time: Certainly growing in the long-term, but perhaps somewhat stagnant of late? The new thirty-year average for 90-degree days in one year at Washington, D.C. (as recorded at National Airport – DCA) is 36.4, down a massive .3 from the 1971-2000 averages. Global cooling?

Note: Though 1871 is included in the historical record, my data does not include daily figures on it so it is redacted from this post and all other daily temperature related historical information on this site. As such, 1871-1900 is a 29-year average in the graphic immediately above.

This post is part of a Washington, D.C. climatology series, both on and off site, that will be maintained at semi regular intervals.

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