Philadelphia Circa 1790

Steven Goddard: From Charles Pierce’s records, the average January temperature in Philadelphia from 1790-1819 was 31.2F. According to USHCN records from 2000-2006 (the last year available from USHCN) and Weather Underground records from 2007-2009, the average January temperature in Philadelphia for the last ten years has been 29.8 degrees, or 1.4 degrees cooler than the period 1790-1819. January, 2009 has been colder than any January during the presidencies of Washington, Adams, Jefferson, or Monroe. January 2003 and 2004 were both considerably colder than any January during the terms of the first five presidents of the US.