Weather-wise.
Today’s Inauguration will be among the coldest ever but other, past inaugurations have seen even colder and nastier weather (click here:) Historians tend to rank Taft’s 1909 inauguration, held the morning after a 10 inch blizzard hit D.C. as the worst ever weather-wise.
And this went down in March before the 20th Amendment moved our Inaugurations back to the current timeframe of January 20th (click here.)
All that noted however, the most impactful, weather-related inauguration has to be that of William Harrison’s in 1841.
Lesson learned – stay warm and dry.