RodneyS

At last, a rainy August 15th at DCA (1.16 inches) and nothing on the 12th. Here are the updated totals, 1871-2016: August 12: 42.55 inches total; 21 days with a trace, 52 days with measurable, 12 days with at least an inch, 5 days with 2+ inches. August 15: 12.28 inches total; 16 days with a trace, 46 days with measurable, 5 days with at least an inch, no days with 2+ inches.

And today marked the 13th consecutive day of at least 90 degrees at DCA, with forecasts tomorrow calling for a high in the mid-80s. Last year we also "officially" had 13 consecutive 90+ readings (during July 24th-August 5th), but that was right before the DCA temperature sensor was replaced on August 10th, with a reference sensor (psychro-dyne) showing a reading of 1.7 degrees too high on the old sensor. Prior to that, DCA had 16 straight 90+ readings July 18-August 2, 2011. The all-time record is 21 straight 90+ readings July 25-August 14, 1980. .

Similar picture for both DCA and IAD, as all three area airports recorded an even 100 degrees. First 100+ at DCA since July 26, 2012, and first at IAD since July 18, 2012. DCA tied the record for July 25th set in 1930 and IAD broke the record of 98 set in 2010.

DCA July 4th maximum of 74 was the lowest since DC's all-time low maximum of 68 on July 4, 1941.

Today marked the 15th consecutive day -- May 24-June 7 -- of a maximum in the 80s at DCA. While the streak is likely over, it did, according to my records, break the all-time DC 80s streak for the first half of the year. I believe that the previous record-holder for that time frame was June 15-28, 1907 (14 days). The all-time record for consecutive days with a maximum in the 80s, I believe, is August 11-September 1, 2001 (22 days).

I have not checked every month in DC history, but I just noticed that May 1953 had 24 days with at least a trace of precipitation at DCA, with 17 days of measurable precipitation there. The corresponding figures for May 2016 are 22 and 19. So, DCA did not exceed the former total this May, but did exceed the latter total.

After failing to reach 80 degrees until May 24th, DCA has now recorded eight consecutive maximums in the 80s. When was the last time that May 24-31 each had maximums in the 80s in DC? Never since official daily temperature record-keeping began in 1872. The closest previously was in 1911, when all but May 30th had maximums in the 80s. However, that day reached an even 90.

Today DCA finally reached 80 degrees in May, the second-latest initial 80-degree May reading in DC history. The latest remains May 26, 1935.

Evidently, the Sunday Dulles report has been corrected to delete the trace of precipitation, and so the official record streak of consecutive days with at least a trace of precipitation there reverts back to 19, April 26-May 14, 2016.

And IAD also tied the record low this morning, but at 36 degrees.

Dulles defied the forecast today and recorded a trace of precipitation, to extend the streak to 20 days.

19 consecutive days it is, but today is likely the end. Still, that beats the old record by six days. Here is the new Top 3 for consecutive days with at least a trace of precipitation at IAD: 1) April 26-May 14, 2016 (19) 2) May 5-17, 1989 (13) 3) June 13-25, 1972 (13)

The same at DCA -- not even a trace there, so the new DC record of consecutive days with measurable precipitation goes into the books at 15, April 27-May 11, 2016. However, the IAD streak of days with at least a trace of precipitation is alive at 17 days, April 26-May 12, with the likelihood of extending to 19 days.

DC has that very same record. I originally thought that the "any precipitation" record streak in DC was 16 (August 9-24, 1920), but I missed the 1935 streak.

DCA sneaked in 0.01 inch late last night, and has already recorded 0.12 inches this morning, so the measurable precipitation streak is now 15.

And late morning rain on Monday extends the streak to lucky 13.

Early morning rain at DCA extends the DC record measurable precipitation streak to 12 days.

I don't know, but PrinceFrederickWx might.

I just posted this on the Capital Weather Gang board: " . . .11 straight days of measurable precipitation at DCA. .. According to my records, that sets the all-time DC record (back to 1871) for most consecutive days of measurable precipitation. I believe that the previous record was ten (twice: August 12-21, 1873 and July 17-26, 1938). During August 9-24, 1920, there were 16 straight days of at least a trace of precipitation, but only seven straight days of measurable."

Assuming that the temperature does not rise to 60 degrees before midnight, an all-time DC record will be set, with each day April 28-May 1 failing to reach 60.

Final three days of April with maximums in the 50s at DCA marked the first time for anything like that since 1966, when the final four days had maximums ranging between 46-59.

Dulles also recorded a low of 24 this morning, tying the record for April 6th set in 1966.

Yes. DCA averaged 53.5 degrees, which was 4th all time -- 3.3 degrees cooler than March 2012. IAD averaged 50.6 degrees, which was 2nd all time -- 3.7 degrees cooler than March 2012.

DCA astronomical (December 21-March 20) and composite (December 1-March 20) winters were even warmer, at 42.8 and 43.9 degrees, respectively. Those averages were good enough for a 5th place tie and 3rd place, respectively, all-time in DC. The comparable averages for 1997-98 were 42.5 and 42.4. The warmest astronomical and composite DC winters each occurred during a weak La Nina in 2011-12, at 45.9 and 45.6, respectively.

The temperature range at DCA that day was 7 to 32. So, the maximum was 3-degrees higher at IAD, but the minimum was 24-degrees lower. As previously mentioned on this thread, that is one of three times that there has been a 24-degree difference between the minimums at the two airports.