look up any word, like the eiffel tower:
 
1.
Sports Fans who only cheer for or pay attention to a team when they are winning. Usually likes to be on the winning side of the coin. Usually looked down upon by serious fans.
Tony: "I thought you were a Florida Fan?"
Rob: "I was last year but I think this year Alabama is winning and I have always kinda liked them a little better"
Tony: "I didn't know you were such Fairweather Johnson, you suck."
by Crimson X October 17, 2010
 
2.
Casual Sports Fans. Defined by Hootie & the Blowfish when asked the meaning of their album of the same name.
Rob is such a Fairweather Johnson, he doesn't even know the Phillies are in the Senior League!
by k-Spit April 27, 2007