RodneyS Posted June 10, 2011 Share Posted June 10, 2011 Yesterday's high of 102 at Reagan tied the all-time DC record for June 9th, and the low of 79 broke the record for that day. That means the average temperature was 90.5 degrees, compared with a 1971-2000 normal of 72.5. Looking at the DC temperature record, it appears that the earliest in the year a 90.5 average had been reached previously was June 29th -- in 1959, when the high was 100 and the low was 81. The next day -- June 30, 1959 -- there was a repeat, and those two days had previously been the only June days in DC with an average temperature as high as 90.5. However, the 1971-2000 normal for those two days is 77.5. So, to achieve a 90.5 average three weeks earlier in the year -- in the astronomical spring, no less -- is quite impressive. Link to comment Share on other sites More sharing options...
MN Transplant Posted June 10, 2011 Share Posted June 10, 2011 I wonder if +18 is the largest departure ever for JJA. Link to comment Share on other sites More sharing options...
Ian Posted June 10, 2011 Share Posted June 10, 2011 I wonder if +18 is the largest departure ever for JJA. Must be close if not. Just about as cool of avgs as we have all summer still. Link to comment Share on other sites More sharing options...
RodneyS Posted June 10, 2011 Author Share Posted June 10, 2011 I wonder if +18 is the largest departure ever for JJA. I would think it would have to be, and you could probably extend that to September as well. Link to comment Share on other sites More sharing options...
Deck Pic Posted June 10, 2011 Share Posted June 10, 2011 I wonder if +18 is the largest departure ever for JJA. yes...no doubt Link to comment Share on other sites More sharing options...
Deck Pic Posted June 10, 2011 Share Posted June 10, 2011 I would think it would have to be, and you could probably extend that to September as well. agreed...99% sure...biggest departure ever for JJAS Link to comment Share on other sites More sharing options...
MN Transplant Posted June 10, 2011 Share Posted June 10, 2011 Sept 24th of last year is close. 99/72 Average 77/59 +17.5 Link to comment Share on other sites More sharing options...
Ian Posted June 10, 2011 Share Posted June 10, 2011 Sept 24th of last year is close. 99/72 Average 77/59 +17.5 i'd think there might be other examples once you get into those average levels.. might as well include may too. some of the readings in the 30s or late 1800s were probably pretty anomalous as well given avgs were probably lower--tho they did not have quite the low temp issue we have today. Link to comment Share on other sites More sharing options...
MN Transplant Posted June 10, 2011 Share Posted June 10, 2011 i'd think there might be other examples once you get into those average levels.. might as well include may too. some of the readings in the 30s or late 1800s were probably pretty anomalous as well given avgs were probably lower--tho they did not have quite the low temp issue we have today. I just quickly checked the record days in late Sept, and I think we are clear of those. May is less likely, found a +18 on the F6 just last year. To your second point, yeah that's the trouble with comparing departures. You have to either say that they are based on the current norms, or have the greatest climo spreadsheet ever that actually has all of the historical norms. Link to comment Share on other sites More sharing options...
RodneyS Posted June 10, 2011 Author Share Posted June 10, 2011 I just quickly checked the record days in late Sept, and I think we are clear of those. May is less likely, found a +18 on the F6 just last year. To your second point, yeah that's the trouble with comparing departures. You have to either say that they are based on the current norms, or have the greatest climo spreadsheet ever that actually has all of the historical norms. I think May 13, 1881 (an unlucky Friday the 13th) is the champ for May-September. The DC temp. range that day was 76-95, for an average of 85.5; vs. a 1971-2000 normal of 55-74, for an average of 64.5 -- therefore, a 21 degree departure. Regarding the second point, temperatures have generally been getting warmer for each 30-year period, but not at the same rate for each of the 12 months. For example, May and June 1971-2000 each averaged about two degrees warmer than May and June 1871-1900, but March 1971-2000 averaged 5.6 degrees warmer than March 1871-1900. So, things get a little tricky, but by any measure yesterday was unusually warm. Link to comment Share on other sites More sharing options...
Deck Pic Posted June 10, 2011 Share Posted June 10, 2011 I think it is safe to say that 6/6/1894 at 49 degrees (high of 52, low of 46) is the biggest negative departure for May-Sep at -23.5....anything even close? Link to comment Share on other sites More sharing options...
RodneyS Posted June 10, 2011 Author Share Posted June 10, 2011 I think it is safe to say that 6/6/1894 at 49 degrees (high of 52, low of 46) is the biggest negative departure for May-Sep at -23.5....anything even close? I don't think so -- the closest I see is September 22, 1904, with a temp range of 39-57, making it 20.5 degrees below normal. June 6, 1894 was an interesting day -- 0.87 inches of rain and yet still a record low of 46. Further, two days earlier the average temperature had been above normal, with a range of 65-91. Link to comment Share on other sites More sharing options...
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