Okay, I went and looked it up. My memory appears to be dreadfully awful.
This is from January 16, 2013, in time for Obozo's second installation:
https://www.washingtonpost.com/blogs/capital-weather-gang/post/washington-dc-presidential-inauguration-weather-history/2013/01/16/5def1200-5ff3-11e2-b05a-605528f6b712_blog.html?utm_term=.cfa7071c8ecfWhere my memory's lousy involves snow.
January 20, 2001 it snowed
January 20, 1969 it rained
January 20, 1961 it snowed (record snowfall)
January 20, 1957 it snowed
January 20, 1945 it snowed
January 20, 1937 it snowed
The five coldest inaugurations have been:
January 20, 1985 07 degrees F
March 4, 1873 16 degrees F
January 20, 1961 20 degrees F
March 4, 1893 25 degrees F
January 20, 2009 28 degrees F
The "average" temperature at January (post-1933) inaugurations have been:
32.5 degrees F when a Democrat's being sworn in
39.3 degrees F when a Republican's being sworn in