Monday, August 1, 2011

July Heat Smashes All-Time Washington/Baltimore Records

Here is the preliminary National Weather Service report confirming the all-time record heat for July 2011 in the Washington/Baltimore region:
..WASHINGTON DC JULY 2011  

HOTTEST JULY AND HOTTEST MONTH EVER...MONTHLY AVERAGE TEMP OF 84.5F
SMASHED PREVIOUS HOTTEST JULY/MONTH AVERAGE OF 83.1F SET JULY 2010
AND JULY 1993.

TWO NEW DAILY RECORD HIGHS WERE SET...102F ON THE 23RD AND 104F ON
THE 30TH.

A READING OF 104F ON JULY 29TH TIED FOR 5TH ALL TIME DAILY HOTTEST
TEMPERATURE EVER. THE HOTTEST DAY IN WASHINGTON SINCE 1872 IS 106F
RECORDED TWICE...JULY 20TH 1930 AND AUGUST 6TH 1918.

MOST NUMBER OF DAYS IN JULY...OR FOR ANY MONTH...WHEN DAILY TEMPS
HIT 90F OR BETTER...25. PREVIOUS HIGHEST TALLY OF DAYS HITTING 90F
OR BETTER...24...IN JULY 1987 AND JULY 1993.

HOTTEST MONTHLY AVERAGE MAX TEMP FOR ANY MONTH INCLUDING JULY...OF
93.6F BEAT THE PREVIOUS RECORD OF 92.8F SET IN JULY 1999.

HIGHEST MONTHLY AVERAGE MIN TEMP FOR ANY MONTH INCLUDING JULY OF
75.4F BEAT THE PREVIOUS RECORD OF 73.9F SET LAST JULY 2010.

A NEW RECORD WAS SET FOR THE NUMBER OF CONSECUTIVE DAYS WHERE THE
TEMPERATURE DID NOT DROP BELOW 80F...4 DAYS FROM THE 21ST THROUGH
THE 25TH.

JULY 2011 FEATURED THE MOST NUMBER OF DAYS FOR ANY MONTH WHERE THE
TEMPERATURES STAYED AT OR ABOVE 80F IN WASHINGTON DC...7.


..BALTIMORE MD JULY 2011

HOTTEST JULY AND HOTTEST MONTH EVER...MONTHLY AVERAGE TEMP OF 81.7F
EDGED THE PREVIOUS HOTTEST JULY/MONTH AVERAGE OF 81.5F SET JULY
2010...JULY 1995...AND JULY 1872.

THREE DAILY RECORD HIGHS WERE EITHER BROKEN...106F ON THE 22ND AND
101F ON THE 29TH...OR TIED...102F ON THE 23RD.

MOST NUMBER OF DAYS IN JULY...OR FOR ANY MONTH...WHEN DAILY TEMPS
HIT 90F OR BETTER...24. PREVIOUS HIGHEST TALLY OF DAYS HITTING 90F
OR BETTER...22...IN JULY 1988 AND JULY 1999.

HOTTEST MONTHLY AVERAGE MAX TEMP FOR ANY MONTH INCLUDING JULY OF
92.9F BEAT THE PREVIOUS RECORD OF 92.5F SET LAST JULY 2010.

A READING OF 106F ON JULY 22ND TIED FOR 2ND ALL TIME DAILY HOTTEST
TEMPERATURE EVER. THE HOTTEST DAY IN BALTIMORE REMAINS 107F RECORDED
IN 1936 ON JULY 10TH.

A NEW DAILY HIGH MIN TEMPERATURE RECORD OF 81F WAS SET ON THE 22ND.

..INTERESTINGLY
THE JULY 2011 MONTHLY AVERAGE MIN TEMP OF 70.4F
RANKED AS THE 24TH WARMEST OF ALL JULYS IN BALTIMORE...AND WAS ONE
TENTH OF A DEGF LESS THAN THE MONTHLY AVERAGE MIN TEMP OF 70.5F FROM
LAST JULY 2010.


..DULLES VA JULY 2011

HOTTEST JULY AND HOTTEST MONTH EVER...MONTHLY AVERAGE TEMP OF 81.0F
SMASHES PREVIOUS HOTTEST JULY/MONTH AVERAGE OF 79.7F SET IN JULY
1993. RECORDING KEEPING AT DULLES BEGAN IN NOVEMBER 1962.

JULY 2011 MARKED THE FIRST TIME EVER AT DULLES THE MONTHLY AVERAGE
TEMPERATURE AVERAGED ABOVE 80F.

THREE DAILY RECORD HIGHS WERE EITHER BROKEN...105F ON THE 22ND AND
103F ON THE 29TH...OR TIED...99F ON THE 23RD.

THE READING OF 105F ON JULY 22ND IS THE HOTTEST ALL TIME TEMPERATURE
EVER RECORDED AT DULLES. THIS BROKE THE PREVIOUS ALL TIME HIGH
TEMPERATURE RECORD OF 104F SET TWICE BEFORE...JULY 16TH 1988 AND
AUGUST 20TH 1983.

MOST NUMBER OF DAYS IN JULY...OR FOR ANY MONTH...WHEN DAILY TEMPS
HIT 90F OR BETTER...24. PREVIOUS HIGHEST TALLY OF DAYS HITTING 90F
OR BETTER...21...IN JULY 1987...JULY 1988 AND JULY 1999.

HOTTEST MONTHLY AVERAGE MAX TEMP FOR ANY MONTH INCLUDING JULY OF
92.8F BEAT THE PREVIOUS RECORD OF 92.5F SET LAST JULY 2010.

2ND HIGHEST MONTHLY AVERAGE MIN TEMP OF 69.1F...SECOND ONLY TO THAT
OF JULY 1994...69.4F.

1 comment:

Anonymous said...

It's going to be interesting to see where this month winds up nationally. It should definitely be a top five -- don't know if it can quite topple 1936 or 2006.

But in terms of temperatures from the Rockies east, I'd say this is probably the hottest month on record. Pretty remarkable how many locations had a record-breaking July. All of the following had their hottest July on record: Wichita Falls, TX; Oklahoma City; Fort Wayne, IN; Detroit; Columbus, OH; Philadelphia, PA; Baltimore; Washington, DC. It was the 2nd hottest in Cleveland; Toledo; Erie, PA; Indianapolis; and Wichita, KS. Most other sites with reliable station threads were well in the top five from Texas to New England.

And, the fact that Baltimore had its hottest mean temp despite having only it's 24th highest average low temp for the month is not too surprising. Contrary to the deniers' claims, a lot of the official records for the bigger cities had more UHI contamination before the official stations were moved out to the airports. Baltimore's temperatures were taken on a rooftop at the Customs House until 1950. Not only is that downtown, but as Watts et al. has shown rooftops can run several degrees warmer than comparable stations sited nearby on the ground. A better comparison for Baltimore's pre-1950 records would be at the Science Center.

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