By Steve Goddard
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.
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.