RodneyS

April 29, 2017 one-upped Easter 2017 by breaking the all-time DC April minimum high temperature record of 69 set way back on April 19, 1896, with today's minimum of 70 at DCA. Today's maximum of 91 there tied the April 29th DC record set in 1974, but fell well short of the all-time DC April maximum record of 95 set on April 27, 1915 and duplicated on April 23, 1960, April 18, 1976, and April 17, 2002. However, today's average temperature of 80.5 also equaled the all-time DC April high average daily temperature record that was established on April 19,1896, which featured a maximum of 92 to go with the 69 minimum.

Using National Weather Service temperature forecasts for the remainder of April results in DCA finishing with an average April 2017 temperature of 63.7 degrees. That would break the April 1994 DC high average record by 1.7 degrees. Also, weighting the first four months of the year equally, January-April 2017 would average 50.2 degrees, breaking the January-April 2012 DC high average record by 0.2 degrees.

Easter 2017 (April 16th) did not establish an all-time high DC Easter maximum (95, set on April 18, 1976) nor an all-time high DC Easter minimum (66, set on April 6, 1947), but did tie the all-time high DC average Easter temperature with a maximum/minimum of 89/65 (average of 77.0), equal to the April 18, 1976 average (95/59).

You're welcome. With all the hype last month about March being colder than February, the cherry blossoms freezing, and the only half-way decent snowstorm of the winter occurring then, I'm guessing 90% of the Mid-Atlantic's population thinks it was an abnormally cold month. :-)

Are you sure? If you weight the first three months of 2017 equally, the first quarter average temperature at DCA was 45.7 degrees, which is third all-time in DC behind only 1Q 2012 (47.3) and 1Q 1990 (46.3).

The mid-March forecasts for the last half of the month at DCA missed the mark on the low side, as the final DCA March 2017 average temperature was 47.2 degrees. Half a degree cooler than February, but still above the 1981-2010 March normal of 46.8. In fact, it tied 1988 as the 49th warmest of 147 Marchs in DC history. Similarly, IAD averaged 44.2 in March 2017, which was 0.6 degrees below February, but exactly equal to the 1981-2010 March normal and tied with 2011 as the 25th warmest of 55 Marchs in IAD history.

The 2016-17 DCA astronomical winter wound up in second place all-time in DC, with an average temperature of 44.3 degrees. The composite winter averaged 43.7, finishing just behind last year and 4th all-time in DC.

The same holds true for DC. I just ran a projection for where March 2017 will finish at DCA based on a composite of the NWS, Weather Channel, and AccuWeather forecasts. The projected March 2017 average temperature works out to be 44.0, which would be 3.7 degrees colder than February 2017, but 1.9 degrees warmer than January 2017 and 2.2 degrees warmer than December 2016.

By the way, DCA's February 2017 average temperature of 47.7 is third all-time warmest for meteorological winter monthly temperatures in DC, behind only December 2015 at 51.2 and January 1950 at 48.0. At Dulles, the February 2017 average temperature of 44.8 is second all-time warmest for meteorological winter, behind only December 2015 at 48.7.

Here are the February 2017 average temperatures for DCA and IAD: DCA -- 47.7 degrees vs previous DC record high of 46.9 in 1976. IAD -- 44.8 vs. previous record high of 42.2 in 1990. IAD also broke its meteorological winter average high temperature record of 40.0 set in 2011-12, with a Dec-Feb average of 40.7. Finally, DCA broke its previous meteorological winter average high temperature record of 43.4 set in 2011-12, with an average of 43.8, but did not break the all-time DC record of 44.7 set in 1931-32 nor equal the 2nd place DC record of 44.3 established in 1889-90.

No record area highs today (both set in 2011 -- 77 at DCA and 74 at IAD), but IAD had an interesting distinction: The 47-degree temperature spread between the morning low of 25 and the afternoon high of 72 was the greatest there since April 8, 1995, when the temperature range was 34 to 81.

New records also at DCA (74) and IAD (71).

Yes indeed. It's interesting that the lowest DC daily January maximum is quite a bit higher than either December's or February's (now 65, on February 3, 1927), at a relatively balmy 68 degrees (on January 3rd, in both 2000 and 2004). At Dulles, it's a different story, as January 10th (2002) is the lowest daily maximum temperature on record, at a mere 58 degrees. Today's high of 72 at IAD easily broke the previous February 7th record of 65 degrees, but the lowest February daily maximum there remains 63 (in both 1990 and 2001). In December, the lowest IAD daily maximum is also 63, set on December 19th (1967).

This January was a different story at DCA, rising to an average temperature of 42.1 degrees vs 41.8 in December 2016. The January average was 12th warmest of all-time in DC, and was 6.1 degrees above the 1981-2010 normal.

The high minimum records at both airports should also fall by day's end. At Dulles, the current record is just 38, set in 2007. Today's low there is currently 49, and is very likely to hold. In DC, the current record is 47, set in 1890. Today's low at DCA is currently 51, and is also very likely to hold.

No contest at Dulles, as today's high of 70 easily eclipsed the previous record of 63 set in 1995. DCA's 72 didn't break the 1890 record of 76, but was the warmest January 12th in DC since that year.

2016 will be the new # 2 in DC, at 60.3 degrees (actually 60.4 if you compute the true 366-day average, rather than averaging the 12 monthly averages). And IAD will also be #2 all-time, at 57.1 (vs. 57.9 in 2012).

Meteorological autumn (September 1-November 30) also was a record setter at DC/DCA, with an average temperature of 63.9 degrees vs. the previous record high of 63.3 in 2007. IAD came up just short, with an average temperature of 60.0 degrees vs. the record high of 60.3 in 2007.

I just discovered that the September 2016 DCA average minimum of 68.6 broke the all-time DC record of 68.2 set in 1881. On the other hand, the September 2016 DCA average maximum of 83.4 didn't even approach the 1881 record of 88.2. In fact, this year's September average maximum was slightly below last year's (83.5) and ranks only 13th all-time.

September 2016 was also a record-setter at IAD (73.1 vs previous record of 72.7 in 1998) and tied for third at DC/DCA (76.0 vs 78.2 in 1881, 77.1 in 1980, and 76.0 in 1930).

You're welcome, and as you have noted, the DCA record of 81.7 for the 1980 astronomical summer is suspect, as it exceeded the IAD temperature of 76.1 by 5.6 degrees. So, a faulty DCA sensor may have been a significant factor in that record.

Astronomical summer (June 21-September 23, on average) was record-setter at IAD (78.0 vs previous record of 76.8 in 2010) and second at DC/DCA (81.1 vs 81.7 in 1980). Also, composite summer (June 1-September 23) was record-setter at both (IAD: 77.1 vs previous record of 76.5 in 2010 and DC/DCA: 80.17 vs previous record of 80.14 in 2010).

It's a longshot at this point, as the 10:52 AM DCA temperature is only 83, vs 88 yesterday at that same time. However, with the old sensor . . .

Yes indeed, good observation -- yesterday was the rainiest August 15th ever in DC. However, 1.16 inches on August 12th would rank as only the 11th rainiest for that day of the year, and so there is still quite a discrepancy between August 12th and August 15th in DC historically. I'm still waiting for some aspiring meterorologist to write his/her Ph.D thesis on this subject.

Yesterday marked the third consecutive 100 degree or higher reading at DCA. The only other time that happened in August in DC was the legendary summer of 1930, which saw August 3-5 do it. If we hit 100 or more today at DCA, that will tie both 1930 (July 19-22) and 2012 (July 5-8) for having the most consecutive days that reached at least 100.