Mild January in Philly

Blog Brother AlexC finds some interesting weather news for his area:

The average or medium temperature of this month was 44 degrees This is the mildest month of January on record. Fogs prevailed very much in the morning but a hot sun soon dispersed them and the mercury often ran up to 70 in the shade at mid day. Boys were often seen swimming in the Delaware and Schuylkill rivers.

That's January 1790. Computed from detailed records kept by Charles Pierce.

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.

In other local weather news, our Minnesota contingent will be pleased to hear that it was unpleasantly cold in Erie, CO for today's dog walk and it should dip below zero tonight.

Deleterious Anthropogenic Warming of the Globe Posted by John Kranz at January 26, 2009 1:32 PM