| American presidents were inaugurated, or put into office, on March 4th in Washington, D.C. Despite Washington's relatively warm climate, inauguration days were often bitterly cold; speeches were held outside, as they still are. This practice began in 1817.
Of course, this is the eighteenth and nineteenth century. Modern medicine as we know it does not exist; as such, too much time spent under cold conditions could be extremely dangerous. Combine this with long inauguration speeches, and you've got a sure recipe for disaster. Examples, you demand?
In 1933, the Twentieth Amendment was passed, moving Inauguration Day to January 20, even deeper into winter. This was due to the fact that presidents who were being removed from office got to stay there right through March, as "lame ducks". Of course, Virginia weather isn't balmy in March, and it certainly isn't that great in January, either. As such, most Americans would be well advised to stay home with the heat turned all the way up, eating fatty foods, until the ceremonies have terminated on TV. | 
