Heatwave In Philadelphia

New high temperature records have been set for Philadelphia:

RECORD EVENT REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
805 AM EDT THU JUL 8 2010

...RECORD TEMPERATURES AT PHILADELPHIA PA WEDNESDAY JULY 7 2010...

A RECORD HIGH TEMPERATURE OF 103 DEGREES WAS SET AT PHILADELPHIA PA
ON WEDNESDAY JULY 7TH. THAT BROKE THE OLD RECORD OF 98 SET IN 1994.

THE WARMEST TEMPERATURES EVER AT PHILADELPHIA WERE 106 ON AUGUST 7
1918.  IT WAS 104 ON JULY 3 1966 AND JULY 10 1936 FOLLOWED BY THE
103 HERE YESTERDAY WHICH ALSO OCCURRED IN SEVERAL OTHER YEARS.

ADDITIONALLY THE LOW OF 80 YESTERDAY WAS ALSO A RECORD WARM MINIMUM
TEMPERATURE FOR THE DATE...SURPASSING THE PREVIOUS RECORD OF 79 IN
1999.

THE AVERAGE TEMPERATURE OF 91.5 YESTERDAY WAS 4TH WARMEST IN
PHILADELPHIA WEATHER HISTORY DATING BACK TO 1872. THE WARMEST
AVERAGE TEMPERATURE WAS 94 DEGREES ON AUGUST 7 1918.

THE TWO CONSECUTIVE DAYS OF 100 DEGREE HEAT WAS THE 4TH WARMEST TWO
DAY PERIOD FOR PHILADELPHIA.

Charles Peirce kept detailed temperature records for Philadelphia from 1790 to 1847

This is what he wrote about July, 1830:

The medium or average temperature of this month was 80; and it was an intensely hot month. At mid-day the mercury rose to 90 and above, on twelve days.

So far this July, Philadelphia has had five days over 90, and the average temperature has been 80.

July, 2010 has been very hot in Philadelphia so far. Just as hot as it was 180 years ago – during the Little Ice Age when CO2 levels were 280 ppm.